Update grpc to 1.42.0, google-protobuf to 3.19

Updates

• grpc and grpc-tools to 1.42.0
• google-protobuf to 3.19

Fixes gitlab#339305 (closed)

google-protobuf changes

• https://github.com/protocolbuffers/protobuf/compare/3.17.x..3.19.x
• https://github.com/protocolbuffers/protobuf/releases

Ruby changes:

• Fix memory leak in MessageClass.encode (#9150)
• Override Map.clone to use Map's dup method (#7938)
• Ruby: build extensions for arm64-darwin (#8232)
• Add class method Timestamp.from_time to ruby well known types (#8562)
• Adopt pure ruby DSL implementation for JRuby (#9047)
• Add size to Map class (#8068)
• Fix for descriptor_pb.rb: google/protobuf should be required first (#9121)
• Update ruby_generator.cc to allow proto2 imports in proto3 (#9003)
• Move DSL implementation from C to pure Ruby (#8850)
• Fixed a memory bug with RepeatedField#+. (#8970)

grpc changes

• https://github.com/grpc/grpc/compare/v1.37.x...v1.42.0
• https://github.com/grpc/grpc/releases

Ruby changes:

• ruby: add arm64 darwin support. (#25992)
• ruby: build native Darwin gems using rake-compiler-dock. (#25794)
• Set XDS user agent in ruby via macros. (#26268)
• ruby: use x86_64 binary on M1 macs. (#25756)
• Add ruby 3.0 support for mac binary packages. (#25429)

Testing & verification

I am personally not in a position to validate these changes and will rely on groupgitaly for this, but I did perform some manual smoke testing in 3 different environments (local, Omnibus, review-app) via gitlab!74987 (merged) and did not encounter any problems. The QA stage also passed in that MR.