This PR cleans up files for owl bot post processor and release please.

Towards googleapis/librarian#2457

Towards googleapis/librarian#2457

This PR resolves the following issue when running `librarian generate`.
Librarian now prevents generated files from clobbering existing files.
All generated files must match `remove_regex` otherwise we will see
errotr like `file existed in destination`


```
time=2025-11-06T20:18:57.185Z level=INFO msg="=== Docker end ================================================================="
time=2025-11-06T20:18:57.185Z level=INFO msg="cleaning directories" "source roots"=[.]
time=2025-11-06T20:18:57.200Z level=INFO msg="copying library files" id=google-cloud-pubsub destination=/usr/local/google/home/partheniou/git/python-pubsub source=/tmp/librarian-2318048050/output/google-cloud-pubsub
time=2025-11-06T20:18:57.201Z level=ERROR msg="failed to generate library" id=google-cloud-pubsub err="file existed in destination: /usr/local/google/home/partheniou/git/python-pubsub/.coveragerc"
time=2025-11-06T20:18:57.201Z level=INFO msg="generation statistics" all=1 successes=0 skipped=0 failures=1
time=2025-11-06T20:18:57.201Z level=ERROR msg="librarian command failed" err="all 1 libraries failed to generate (skipped: 0)"
```

Command used

```
librarian generate --generate-unchanged
```

This PR updates the librarian container sha for v1.0.0 support.

---------

Co-authored-by: Anthonios Partheniou <[email protected]>

chore: librarian update image pull request: 20251216T203515Z

PR created by the Librarian CLI to initialize a release. Merging this PR
will auto trigger a release.

Librarian Version: v0.7.0
Language Image:
us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:b8058df4c45e9a6e07f6b4d65b458d0d059241dd34c814f151c8bf6b89211209
<details><summary>google-cloud-pubsub: 2.34.0</summary>

##
[2.34.0](v2.33.0...v2.34.0)
(2025-12-16)

### Features

* support mTLS certificates when available (#1566)
([24761a2](24761a2f))

</details>