Bump grpcio from 1.47.0 to 1.48.1 in /tests (#3008)

Bumps [grpcio](https://github.com/grpc/grpc) from 1.47.0 to 1.48.1.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.47.0...v1.48.1)

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

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ciara Stacke <18287516+ciarams87@users.noreply.github.com>

tests/requirements.txt

@@ -11,6 +11,6 @@ pytest-html==3.1.1
 pytest-profiling==1.7.0
 more-itertools==8.14.0
 mock==4.0.3
-grpcio==1.47.0
+grpcio==1.48.1
 grpcio-tools==1.47.0
 flaky==3.7.0