Remove deprecated spool queue from Beats

[kvch]

What does this PR do?

This PR removes the deprecated disk spool queue from libbeat.

Why is it important?

The feature hasn't been GAed. Instead it was deprecated in favour of the disk queue: https://www.elastic.co/guide/en/beats/filebeat/current/configuring-internal-queue.html#configuration-internal-queue-disk

Checklist

- [ ] My code follows the style guidelines of this project
- [ ] I have commented my code, particularly in hard-to-understand areas

• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
  - [ ] I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[mergify]

This pull request does not have a backport label. Could you fix it @kvch? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 7./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[botelastic]

This pull request doesn't have a Team:<team> label.

[elasticmachine]

💔 Tests Failed

the below badges are clickable and redirect to their specific view in the CI or DOCS

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Build stats

• Start Time: 2021-11-22T15:21:06.407+0000

• Duration: 111 min 54 sec

• Commit: d5023a9

Test stats 🧪

Test	Results
Failed	1
Passed	19916
Skipped	1363
Total	21280

Test errors

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Build&Test / metricbeat-pythonIntegTest / test_metricsets_0_stats – metricbeat.tests.system.test_beat.Test

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 Exception: Key 'beat.stats.beat.uuid' found in event is not documented! 

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 a = (<test_beat.Test testMethod=test_metricsets_0_stats>,)

    @wraps(func)
    def standalone_func(*a):
>       return func(*(a + p.args), **p.kwargs)

../build/ve/docker/lib/python3.9/site-packages/parameterized/parameterized.py:518: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
tests/system/test_beat.py:21: in test_metricsets
    self.check_metricset("beat", metricset, [self.compose_host("metricbeat")], self.FIELDS + ["service"])
tests/system/metricbeat.py:107: in check_metricset
    self.assert_fields_are_documented(evt)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <test_beat.Test testMethod=test_metricsets_0_stats>
evt = {'@timestamp': '2021-11-22T16:50:27.325Z', 'agent': {'ephemeral_id': '5e3090ed-ecc1-4a93-a70f-c41593a1c783', 'id': '7f...limit': {'hard': 1048576, 'soft': 1048576}, 'open': 10}, ...}, 'type': 'metricbeat'}, 'ecs': {'version': '8.0.0'}, ...}

    def assert_fields_are_documented(self, evt):
        """
        Assert that all keys present in evt are documented in fields.yml.
        This reads from the global fields.yml, means `make collect` has to be run before the check.
        """
        expected_fields, dict_fields, aliases = self.load_fields()
        flat = self.flatten_object(evt, dict_fields)
    
        def field_pattern_match(pattern, key):
            pattern_fields = pattern.split(".")
            key_fields = key.split(".")
            if len(pattern_fields) != len(key_fields):
                return False
            for i in range(len(pattern_fields)):
                if pattern_fields[i] == "*":
                    continue
                if pattern_fields[i] != key_fields[i]:
                    return False
            return True
    
        def is_documented(key, docs):
            if key in docs:
                return True
            for pattern in (f for f in docs if "*" in f):
                if field_pattern_match(pattern, key):
                    return True
            return False
    
        for key in flat.keys():
            metaKey = key.startswith('@metadata.')
            # Range keys as used in 'date_range' etc will not have docs of course
            isRangeKey = key.split('.')[-1] in ['gte', 'gt', 'lte', 'lt']
            if not(is_documented(key, expected_fields) or metaKey or isRangeKey):
>               raise Exception("Key '{}' found in event is not documented!".format(key))
E               Exception: Key 'beat.stats.beat.uuid' found in event is not documented!

../libbeat/tests/system/beat/beat.py:732: Exception 

Steps errors

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libbeat-stress-tests - make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stres

• Took 10 min 17 sec . View more details here
• Description: make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stress-tests

libbeat-stress-tests - make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stres

• Took 10 min 3 sec . View more details here
• Description: make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stress-tests

libbeat-stress-tests - make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stres

• Took 10 min 4 sec . View more details here
• Description: make STRESS_TEST_OPTIONS='-timeout=20m -race -v -parallel 1' -C libbeat stress-tests

metricbeat-pythonIntegTest - mage pythonIntegTest

• Took 31 min 52 sec . View more details here
• Description: mage pythonIntegTest

metricbeat-pythonIntegTest - mage pythonIntegTest

• Took 22 min 46 sec . View more details here
• Description: mage pythonIntegTest

metricbeat-pythonIntegTest - mage pythonIntegTest

• Took 22 min 50 sec . View more details here
• Description: mage pythonIntegTest

Error signal

• Took 0 min 0 sec . View more details here
• Description: Error 'hudson.AbortException: script returned exit code 2'

🐛 Flaky test report

❕ There are test failures but not known flaky tests.

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Genuine test errors

💔 There are test failures but not known flaky tests, most likely a genuine test failure.

• Name: Build&Test / metricbeat-pythonIntegTest / test_metricsets_0_stats – metricbeat.tests.system.test_beat.Test

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /package : Generate the packages and run the E2E tests.

• /beats-tester : Run the installation tests with beats-tester.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[kvch]

Failing tests are fixed in #29094

[faec]

beautiful :D