chore(all): auto-regenerate .pb.go files (#752)

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#5449

Changes:

chore: use gapic-generator-python 0.63.1
  docs: add autogenerated code snippets
  PiperOrigin-RevId: 426256923
  Source-Link: googleapis/googleapis@9ebabfa

chore(ruby): Regenerate using Ruby microgenerator 0.10.6
  PiperOrigin-RevId: 426223384
  Source-Link: googleapis/googleapis@e34d712

feat(channel): Change description for GCP ProvisionedService.provisioning_id value feat: Update year from 2021 to 2022
  PiperOrigin-RevId: 426206624
  Source-Link: googleapis/googleapis@4eca5ca

chore: regenerate API index

  Source-Link: googleapis/googleapis@66759bd

feat(documentai): add question_id field in ReviewDocumentOperationMetadata
  PiperOrigin-RevId: 426180523
  Source-Link: googleapis/googleapis@38a8eb9

regen.txt

@@ -1 +1 @@
-2b37083027fcfa408ee75eee4264cad7c2de0a67
+9ebabfa115341b8016b6ed64b22c04260360a8ff