Bump protobuf from 4.25.3 to 5.28.0

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 4.25.3 to 5.28.0.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v4.25.3...v5.28.0)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -5,6 +5,6 @@ litecli == 1.11.0
 google-cloud-logging == 3.11.2
 google-compute-engine == 2.8.13
 gunicorn == 23.0.0
-protobuf == 4.25.3
+protobuf == 5.28.0
 requests == 2.32.3
 supervisor == 4.2.5