Bump protobuf in /ai/gen-ai-agents/custom-rag-agent

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 5.29.3 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@v5.29.3...v5.29.5)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

ai/gen-ai-agents/custom-rag-agent/requirements.txt

@@ -142,7 +142,7 @@ platformdirs==4.3.6
 prometheus_client==0.21.1
 prompt_toolkit==3.0.50
 propcache==0.3.0
-protobuf==5.29.3
+protobuf==5.29.5
 psutil==7.0.0
 ptyprocess==0.7.0
 pure_eval==0.2.3