Bump protobuf from 3.9.0 to 3.18.3

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.9.0 to 3.18.3.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.9.0...v3.18.3)

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

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

requirements.txt

@@ -5,7 +5,7 @@ lazy-object-proxy==1.4.1
 mccabe==0.6.1
 numpy==1.17.0
 pika==1.1.0
-protobuf==3.9.0
+protobuf==3.18.3
 pylint==2.3.1
 pymongo==3.8.0
 python-dotenv==0.10.3