Bump grpcio-tools from 1.37.0 to 1.68.0 in /sdks/python

Bumps [grpcio-tools](https://github.com/grpc/grpc) from 1.37.0 to 1.68.0.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.37.0...v1.68.0)

---
updated-dependencies:
- dependency-name: grpcio-tools
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

sdks/python/build-requirements.txt

@@ -20,7 +20,7 @@
 setuptools
 wheel>=0.36.0
 
-grpcio-tools==1.37.0
+grpcio-tools==1.68.0
 mypy-protobuf==1.18
 
 # Avoid https://github.com/pypa/virtualenv/issues/2006