chore(all): auto-regenerate .pb.go files (googleapis#634)

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#4393

Changes:

chore: regenerate API index
  
  Source-Link: googleapis/googleapis@1986171

feat: added a new API method ListBuildTargets to list build targets that a user has access to
  This API method does not require a input for the user account. It will fetch the current user account from the service account credential file automatically.
  
  PiperOrigin-RevId: 383511703
  Source-Link: googleapis/googleapis@cdb30b6

feat(pubsub): Add method signature for Subscriber.Pull without the deprecated return_immediately field.
  PiperOrigin-RevId: 383459959
  Source-Link: googleapis/googleapis@fe3cc5e

chore: regenerate API index
  
  Source-Link: googleapis/googleapis@b755d25

feat(monitoring/dashboard): added validation only mode when writing dashboards feat: added alert chart widget
  PiperOrigin-RevId: 383440655
  Source-Link: googleapis/googleapis@b5532bb

build(vpcaccess): update package name
  PiperOrigin-RevId: 383434153
  Source-Link: googleapis/googleapis@a9d8182