Bump mypy-protobuf from 1.18 to 3.4.0 in /sdks/python

Bumps [mypy-protobuf](https://github.com/nipunn1313/mypy-protobuf) from 1.18 to 3.4.0.
- [Release notes](https://github.com/nipunn1313/mypy-protobuf/releases)
- [Changelog](https://github.com/nipunn1313/mypy-protobuf/blob/main/CHANGELOG.md)
- [Commits](nipunn1313/mypy-protobuf@v1.18...v3.4.0)

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

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

Author: dependabot[bot]

sdks/python/build-requirements.txt

@@ -24,7 +24,7 @@ grpcio-tools==1.37.0
 # TODO(https://github.com/apache/beam/issues/23734): the sdist for grpcio==1.50.0 is failing on GH workers
 # pin grpcio to the previous version.
 grpcio==1.49.1;sys_platform=="darwin"
-mypy-protobuf==1.18
+mypy-protobuf==3.4.0
 protobuf==3.19.4;python_version=="3.10" and sys_platform=="darwin"
 
 # Avoid https://github.com/pypa/virtualenv/issues/2006