cmd/protoc-gen-go-grpc: update version for release (grpc#5070)

Change version to 1.43.0 (grpc#5039)

Change version to 1.44.0-dev (grpc#5041)

Change version to 1.41.1 (grpc#5027)

Change version to 1.40.1 (grpc#5028)

Change version to 1.42.0 (grpc#4910)

[skip ci] Skipping Travis. Version number change only

Co-authored-by: Doug Fawley <dfawley@google.com>

Change version to 1.43.0-dev (grpc#4912)

backport PRs to v1.41.x (grpc#4810)

* xds: fix parent balancers to handle Idle children (grpc#4801)
* transport: fix log spam from Server Authentication Handshake errors (grpc#4798)

Change version to 1.42.0-dev (grpc#4793)

server: fix leaked net.Conn (grpc#4644) (grpc#4670)