chore(deps): bump grpcio from 1.76.0 to 1.78.0 in /backend/python/coqui

Bumps [grpcio](https://github.com/grpc/grpc) from 1.76.0 to 1.78.0.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Commits](https://github.com/grpc/grpc/compare/v1.76.0...v1.78.0)

---
updated-dependencies:
- dependency-name: grpcio
  dependency-version: 1.78.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/python/coqui/requirements.txt

@@ -1,4 +1,4 @@
-grpcio==1.76.0
+grpcio==1.78.0
 protobuf
 certifi
 packaging==24.1