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#4072

Changes:

chore: Update gapic-generator-php dependency version
  PiperOrigin-RevId: 372514420
  Source-Link: googleapis/googleapis@94a788e

fix: use require() to load JSON protos
  The library is regenerated with gapic-generator-typescript v1.3.1.

  Committer: @alexander-fenster
  PiperOrigin-RevId: 372468161
  Source-Link: googleapis/googleapis@75880c3

chore: Remove unused aiplatform_gapic.yaml
  Committer: @miraleung
  PiperOrigin-RevId: 372463367
  Source-Link: googleapis/googleapis@4d01d63

chore: release gapic-generator-php v0.1.3
  Committer: @miraleung
  PiperOrigin-RevId: 372462573
  Source-Link: googleapis/googleapis@3a2dfb5

chore: release gapic-generator-php v0.1.2
  Committer: @miraleung
  PiperOrigin-RevId: 372403008
  Source-Link: googleapis/googleapis@6b3f5af

feat(dialogflow/cx): add support for service directory webhooks
  PiperOrigin-RevId: 372385924
  Source-Link: googleapis/googleapis@0506eca

feat(cloudbuild/apiv1): Implementation of Source Manifests: - Added message StorageSourceManifest as an option for the Source message - Added StorageSourceManifest field to the SourceProvenance message
  PiperOrigin-RevId: 372331161
  Source-Link: googleapis/googleapis@87a6ce5