chore(all): auto-regenerate .pb.go files (googleapis#655)

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#4615

Changes:

feat:Publish Workflows call logging proto for documentation
  PiperOrigin-RevId: 390391198
  Source-Link: googleapis/googleapis@c47ff19

fix: Update DocumentUnderstandingService default_host in v1beta2 from a regional endpoint, to non-regional
  Committer: @nicain
  PiperOrigin-RevId: 390219495
  Source-Link: googleapis/googleapis@09a6183

chore: regenerate API index

  Source-Link: googleapis/googleapis@08ae683

feat(googleads): protos for v8.1 of Google Ads API
  Committer: @aohren
  PiperOrigin-RevId: 390218328
  Source-Link: googleapis/googleapis@6ef6c29

chore: regenerate API index

  Source-Link: googleapis/googleapis@eb7c9d1

chore(secretmanager): no-op proto generator run to pickup Locations service metadata
  PiperOrigin-RevId: 390124312
  Source-Link: googleapis/googleapis@f5e39a2