build(deps): bump protobuf from 6.32.1 to 6.33.5 in /samples/snippets

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 6.32.1 to 6.33.5.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Commits](https://github.com/protocolbuffers/protobuf/commits)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-version: 6.33.5
  dependency-type: direct:production
...

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

Author: dependabot[bot]

samples/snippets/requirements.txt

@@ -1,6 +1,6 @@
 google-cloud-pubsub==2.31.1
 avro==1.12.0
-protobuf==6.32.1
+protobuf==6.33.5
 avro==1.12.0
 opentelemetry-api==1.37.0
 opentelemetry-sdk==1.37.0