feat: Add support for apiEndpoint and deprecate serviceAddress client configuration option.

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Here's the log from Synthtool:

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/OsLogin/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
0.29.1: Pulling from googleapis/artman
Digest: sha256:b2a73f4dda03ef8fcaa973e3ba26d0cf34091f6c22c70add663af325931aef4d
Status: Image is up to date for googleapis/artman:0.29.1
synthtool > Cloning googleapis.
synthtool > Running generator for google/cloud/oslogin/artman_oslogin_v1beta.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/php/google-cloud-os-login-v1beta.
synthtool > Running generator for google/cloud/oslogin/artman_oslogin_v1.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/php/google-cloud-os-login-v1.
synthtool > Replaced "'serviceAddress' =>" in src/V1beta/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced "'serviceAddress' =>" in src/V1/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced '@type string \\$serviceAddress' in src/V1beta/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced '@type string \\$serviceAddress' in src/V1/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced '\\$transportConfig, and any \\$serviceAddress' in src/V1beta/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced '\\$transportConfig, and any \\$serviceAddress' in src/V1/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta/OsLoginServiceClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta/OsLoginServiceGrpcClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1beta/OsLoginServiceClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/System/V1beta/OsLoginServiceClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/OsLoginServiceClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/OsLoginServiceGrpcClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/Gapic/OsLoginServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1/OsLoginServiceClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/System/V1/OsLoginServiceClientTest.php.
synthtool > Cleaned up 1 temporary directories.
synthtool > Wrote metadata to synth.metadata.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@2a8a0c4). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             master   #2217   +/-   ##
========================================
  Coverage          ?   92.6%           
  Complexity        ?    4451           
========================================
  Files             ?     307           
  Lines             ?   13271           
  Branches          ?       0           
========================================
  Hits              ?   12290           
  Misses            ?     981           
  Partials          ?       0

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