build(deps-dev): bump grpc/grpc from 1.74.0 to 1.78.0

Bumps [grpc/grpc](https://github.com/grpc/grpc-php) from 1.74.0 to 1.78.0.
- [Commits](grpc/grpc-php@v1.74.0...v1.78.0)

---
updated-dependencies:
- dependency-name: grpc/grpc
  dependency-version: 1.78.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]