Bump grpcio from 1.51.0 to 1.51.1 in /tests (#3324)

Bumps [grpcio](https://github.com/grpc/grpc) from 1.51.0 to 1.51.1.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.51.0...v1.51.1)

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

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

tests/requirements.txt

@@ -2,7 +2,7 @@ certifi==2022.9.24
 cffi==1.15.1
 flaky==3.7.0
 forcediphttpsadapter==1.0.2
-grpcio==1.51.0
+grpcio==1.51.1
 grpcio-tools==1.51.0
 kubernetes==25.3.0
 mock==4.0.3