Bump protobuf in /ai/gen-ai-agents/assistant-secretary-agent/files

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 5.28.3 to 5.29.5.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v5.28.3...v5.29.5)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-version: 5.29.5
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

ai/gen-ai-agents/assistant-secretary-agent/files/local_requirements.txt

@@ -61,7 +61,7 @@ pexpect==4.9.0
 pillow==11.0.0
 prompt_toolkit==3.0.50
 propcache==0.2.0
-protobuf==5.28.3
+protobuf==5.29.5
 ptyprocess==0.7.0
 pure_eval==0.2.3
 pyarrow==18.1.0