Bump the ruby group with 2 updates

Bumps the ruby group with 2 updates: [grpc](https://github.com/google/grpc) and [grpc-tools](https://github.com/google/grpc).


Updates `grpc` from 1.63.0 to 1.64.0
- [Release notes](https://github.com/google/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.63.0...v1.64.0)

Updates `grpc-tools` from 1.63.0 to 1.64.0
- [Release notes](https://github.com/google/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/src/ruby/CHANGELOG.md)
- [Commits](grpc/grpc@v1.63.0...v1.64.0)

---
updated-dependencies:
- dependency-name: grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: ruby
- dependency-name: grpc-tools
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: ruby
...

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

Gemfile.lock

@@ -19,22 +19,22 @@ GEM
     google-protobuf (3.25.3-x86_64-linux)
     googleapis-common-protos-types (1.14.0)
       google-protobuf (~> 3.18)
-    grpc (1.63.0)
+    grpc (1.64.0)
       google-protobuf (~> 3.25)
       googleapis-common-protos-types (~> 1.0)
-    grpc (1.63.0-aarch64-linux)
+    grpc (1.64.0-aarch64-linux)
       google-protobuf (~> 3.25)
       googleapis-common-protos-types (~> 1.0)
-    grpc (1.63.0-arm64-darwin)
+    grpc (1.64.0-arm64-darwin)
       google-protobuf (~> 3.25)
       googleapis-common-protos-types (~> 1.0)
-    grpc (1.63.0-x86_64-darwin)
+    grpc (1.64.0-x86_64-darwin)
       google-protobuf (~> 3.25)
       googleapis-common-protos-types (~> 1.0)
-    grpc (1.63.0-x86_64-linux)
+    grpc (1.64.0-x86_64-linux)
       google-protobuf (~> 3.25)
       googleapis-common-protos-types (~> 1.0)
-    grpc-tools (1.63.0)
+    grpc-tools (1.64.0)
     method_source (1.1.0)
     os (1.1.4)
     parser (3.3.1.0)