Regeneration check found diff

The post-submit [regeneration check](https://github.com/googleapis/google-cloud-python/actions/runs/27358048245) found a diff.

 Diff summary:
 ```
 .../snippets/filters/filter_snippets_async_test.py | 4 +---
 .../samples/snippets/reads/read_snippets.py | 1 +
 .../google-cloud-bigtable/samples/testdata/singer_pb2.py | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 3 deletions(-)
 ```