Bump protobuf from 4.24.4 to 4.25.8 in /python-rag-chatbot

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 4.24.4 to 4.25.8.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v4.24.4...v4.25.8)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-version: 4.25.8
  dependency-type: direct:production
...

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

Author: dependabot[bot]

python-rag-chatbot/requirements.txt

@@ -159,7 +159,7 @@ platformdirs==                             3.11.0
 posthog==                                  3.0.2
 prometheus-client==                        0.17.1
 prompt-toolkit==                           3.0.39
-protobuf==                                 4.24.4
+protobuf== 4.25.8
 psutil==                                   5.9.6
 ptyprocess==                               0.7.0
 pulsar-client==                            3.5.0