chore(all): auto-regenerate .pb.go files

This is an auto-generated regeneration of the .pb.go files by
cloud.google.com/go/internal/gapicgen. Once this PR is submitted, genbot will
update the corresponding PR to depend on the newer version of go-genproto, and
assign reviewers. Whilst this or any regen PR is open in go-genproto, genbot
will not create any more regeneration PRs. If all regen PRs are closed,
gapicgen will create a new set of regeneration PRs once per night.

If you have been assigned to review this PR, please:

- Ensure that CI is passing. If it's failing, it requires your manual attention.
- Approve and submit this PR if you believe it's ready to ship. That will prompt
genbot to assign reviewers to the google-cloud-go PR.

Corresponding google-cloud-go PR: googleapis/google-cloud-go#4138

Changes:

chore: regenerate API index

  Source-Link: googleapis/googleapis@599fed8

chore: Add package/namespace options for C#, Ruby and PHP. This is a breaking change *only* for those languages, and packages for those languages have not been published yet.
  PiperOrigin-RevId: 374806479
  Source-Link: googleapis/googleapis@380f0f3

chore: regenerate API index

  Source-Link: googleapis/googleapis@a8b1261

chore(serviceusage): Add package/namespace options for C#, Ruby and PHP. This is a breaking change *only* for those languages, and packages for those languages have not been published yet.
  PiperOrigin-RevId: 374806200
  Source-Link: googleapis/googleapis@e3be492

chore: regenerate API index

  Source-Link: googleapis/googleapis@4698c32

chore: update Go generator to v0.20.0
  PiperOrigin-RevId: 374507151
  Source-Link: googleapis/googleapis@b5a6598

chore: move action to workflows directory
  PiperOrigin-RevId: 374504512
  Source-Link: googleapis/googleapis@fab7e8d

docs(dialogflow/cx): clarified documentation for security settings docs: clarified documentation for session parameters
  PiperOrigin-RevId: 374474736
  Source-Link: googleapis/googleapis@c27d046

docs(dialogflow/cx): clarified documentation for security settings docs: clarified documentation for session parameters
  PiperOrigin-RevId: 374473298
  Source-Link: googleapis/googleapis@f57b0b7

feat: added location-aware HTTP path binding for ListIntents feat: exposed match confidence and parameter in AnalyzeContentResponse feat: added DTMF and PARTIAL DTMF type in recognition result
  PiperOrigin-RevId: 374460003
  Source-Link: googleapis/googleapis@1309578

feat: Add ListSampleProjects endpoint, Canvas response fullscreen, Media response repeat, and entity set.
  PiperOrigin-RevId: 374447959
  Source-Link: googleapis/googleapis@0f9e69b