Bump protobuf from 3.6.1 to 3.18.3

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.6.1 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@v3.6.1...v3.18.3)

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

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

Author: dependabot[bot]

requirements.txt

@@ -106,7 +106,7 @@ ply==3.11
 preshed==2.0.1
 prometheus-client==0.5.0
 prompt-toolkit==2.0.7
-protobuf==3.6.1
+protobuf==3.18.3
 psutil==5.4.7
 psycopg2==2.7.4
 ptyprocess==0.6.0