Bump protobuf from 4.25.3 to 4.25.8 in /examples/gunicorn

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 4.25.3 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@v4.25.3...v4.25.8)

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

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

Author: dependabot[bot]

examples/gunicorn/poetry.lock

@@ -10,7 +10,7 @@ python = "^3.10"
 gunicorn = "^22.0.0"
 prefab-cloud-python = {path = "../..", develop = true}
 cachetools = "5.3.2"
-protobuf = "^4.25.2"
+protobuf = "^4.25.8"
 
 
 [build-system]