Bump protobuf and protoc_plugin (#2723) Bumps [protobuf](https://github.com/google/protobuf.dart) and [protoc_plugin](https://github.com/google/protobuf.dart). These dependencies needed to be updated together. Updates `protobuf` from 5.1.0 to 6.0.0 - [Release notes](https://github.com/google/protobuf.dart/releases) - [Commits](https://github.com/google/protobuf.dart/compare/protobuf-v5.1.0...protobuf-v6.0.0) Updates `protoc_plugin` from 24.0.0 to 25.0.0 - [Release notes](https://github.com/google/protobuf.dart/releases) - [Commits](https://github.com/google/protobuf.dart/compare/protoc_plugin-v24.0.0...protoc_plugin-v25.0.0) --- updated-dependencies: - dependency-name: protobuf dependency-version: 6.0.0 dependency-type: direct:production update-type: version-update:semver-major - dependency-name: protoc_plugin dependency-version: 25.0.0 dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>