Bump protobuf from 6.31.0 to 6.31.1 in /ai/gen-ai-agents/travel_agent

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 6.31.0 to 6.31.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v6.31.0...v6.31.1)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-version: 6.31.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

ai/gen-ai-agents/travel_agent/requirements.txt

@@ -112,7 +112,7 @@ platformdirs==4.3.8
 prometheus_client==0.22.0
 prompt_toolkit==3.0.51
 propcache==0.3.1
-protobuf==6.31.0
+protobuf==6.31.1
 psutil==7.0.0
 ptyprocess==0.7.0
 pure_eval==0.2.3