Bump the minor group with 3 updates

Bumps the minor group with 3 updates: [grpcio](https://github.com/grpc/grpc), [flake8](https://github.com/pycqa/flake8) and [grpcio-tools](https://github.com/grpc/grpc).


Updates `grpcio` from 1.72.1 to 1.73.1
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.72.1...v1.73.1)

Updates `flake8` from 7.2.0 to 7.3.0
- [Commits](PyCQA/flake8@7.2.0...7.3.0)

Updates `grpcio-tools` from 1.72.1 to 1.73.1
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.72.1...v1.73.1)

---
updated-dependencies:
- dependency-name: grpcio
  dependency-version: 1.73.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: minor
- dependency-name: flake8
  dependency-version: 7.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: minor
- dependency-name: grpcio-tools
  dependency-version: 1.73.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -11,8 +11,8 @@ requires = [
   # versions can't work with code that was generated with newer versions.
   # https://protobuf.dev/support/cross-version-runtime-guarantee/#backwards
   "protobuf == 6.31.1",
-  "grpcio-tools == 1.72.1",
-  "grpcio == 1.72.1",
+  "grpcio-tools == 1.73.1",
+  "grpcio == 1.73.1",
 
 ]
 build-backend = "setuptools.build_meta"
@@ -62,7 +62,7 @@ email = "floss@frequenz.com"
 
 [project.optional-dependencies]
 dev-flake8 = [
-  "flake8 == 7.2.0",
+  "flake8 == 7.3.0",
   "flake8-docstrings == 1.7.0",
   "flake8-pyproject == 1.2.3", # For reading the flake8 config from pyproject.toml
   "pydoclint == 0.6.6",