chore: add release-please automation

[willarmiros]

Which problem is this PR solving?

• Partially Package Ownership #605

Short description of the changes

• Adds release-please automated independent release workflow so that individual packages can be released at their own cadence
• Pretty much a dupe of chore: add release-please automation opentelemetry-js#2431 but for contrib

I tested these changes via an identical action in a dummy repo. You can see it completing a successful release here: https://github.com/willarmiros/test-package-lock-repo/runs/3618032476?check_suite_focus=true

[codecov]

Codecov Report

Merging #659 (ceb75c1) into main (e7e0e00) will decrease coverage by 1.60%.
The diff coverage is n/a.

❗ Current head ceb75c1 differs from pull request most recent head 77b0708. Consider uploading reports for the commit 77b0708 to get more accurate results

@@            Coverage Diff             @@
##             main     #659      +/-   ##
==========================================
- Coverage   96.68%   95.08%   -1.61%     
==========================================
  Files          13      173     +160     
  Lines         634    12267   +11633     
  Branches      124     1172    +1048     
==========================================
+ Hits          613    11664   +11051     
- Misses         21      603     +582     

Impacted Files	Coverage Δ
...metry-instrumentation-document-load/src/version.ts
...ry-instrumentation-user-interaction/src/version.ts
...extension-autoinjection/test/contentScript.test.ts	100.00% <0.00%> (ø)
...metry-instrumentation-memcached/test/index.test.ts	93.47% <0.00%> (ø)
...ntelemetry-instrumentation-dns/test/utils/utils.ts	33.33% <0.00%> (ø)
...ource-detector-aws/src/detectors/AwsEcsDetector.ts	100.00% <0.00%> (ø)
...detector-aws/src/detectors/AwsBeanstalkDetector.ts	95.65% <0.00%> (ø)
...-instrumentation-nestjs-core/src/enums/NestType.ts	100.00% <0.00%> (ø)
...metry-resource-detector-aws/src/detectors/index.ts	100.00% <0.00%> (ø)
...de/opentelemetry-instrumentation-hapi/src/types.ts	100.00% <0.00%> (ø)
... and 156 more

[willarmiros]

I'll leave this as a draft since it's blocked on #657, which ought to be the final manual, repo-wide release in contrib. But it is ready for review, apart from updating RELEASING.md.

[dyladan]

The manifest will be regenerated anyway on the next release so having extra entries is actually not a problem. Missing entries would be a bigger deal.

[willarmiros]

@dyladan Do we want to also include releasing to NPM & GitHub in the release-please workflow as part of this PR, or should we do that in a separate PR? Reference: https://github.com/googleapis/release-please#automating-publication-to-npm

[dyladan]

@willarmiros whatever is easier for you

[willarmiros]

@dyladan I'll just update this PR to include the NPM and GH release steps

[willarmiros]

@obecny @vmarchaud I've finished the release-please automation for contrib and tested it as stated in description. PTAL if you have a chance :)

[vmarchaud]

lgtm

[obecny]

from code perspective it looks fine, but I will defer the review to @dyladan who is more familiar with releasing

[dyladan]

Looks good just some minor clarifications

[dyladan]

Is releases meant to be plural? I might be misremembering but i thought it was singular.

[willarmiros]

Yeah I believe their README is incorrect. I submitted a PR to correct it: googleapis/release-please#1057

Based on my output from this test run it's plural: https://github.com/willarmiros/test-package-lock-repo/runs/3617992025?check_suite_focus=true#step:3:4

[willarmiros]

@dyladan is this ready for merging?