Reference: go/librarian:commits

Here is the format of generation pull requests

feat: API regeneration: {date}

This pull request is generated with proto changes between
[googleapis/googleapis@{start_commit_hash}](https://github.com/googleapis/googleapis/commit/{start_commit_hash})
(exclusive) and
[googleapis/googleapis@{end_commit_hash}](https://github.com/googleapis/googleapis/commit/{end_commit_hash})
(inclusive).

Librarian Version: {librarian_version}
Language Image: {language_image_name_and_digest}

BEGIN_COMMIT_OVERRIDE
BEGIN_NESTED_COMMIT
{type}: [{library}] {subject}
{body}
...

PiperOrigin-RevId: {piper_cl_number}

Source-link:
[googleapis/googleapis@{source_commit_hash}](https://github.com/googleapis/googleapis/commit/{source_commit_hash})
END_NESTED_COMMIT
...
END_COMMIT_OVERRIDE

A generation pull request bundles a range of commits from googleapis into a single pull request and a single commit, potentially affecting multiple libraries. The PR title, which becomes the first line of the merged commit, will always be a feat type and will not include a breaking change indicator (!), ensuring that generation PRs result in a minor version bump by default. The description preserves the individual commit messages from the source repository using BEGIN_COMMIT_OVERRIDE and BEGIN_NESTED_COMMIT markers to ensure traceability. Librarian will also determine and populate the {library} and the {piper_cl_number} properties in the commit messages, augmenting the original messages provided by the API producers. Upon merging the PR, the resulting commit message will be the same as the PR title and description, allowing potentially skipping the PR entirely in the future.

Blocked by: #1706