Bump protobuf-java from 3.9.2 to 3.16.3 in /tensorflow/java/maven/proto#16

dependabot[bot] wants to merge 1 commit intor2.6/sdk-release-3.4graphcore/tensorflow:r2.6/sdk-release-3.4from

dependabot/maven/tensorflow/java/maven/proto/com.google.protobuf-protobuf-java-3.16.3graphcore/tensorflow:dependabot/maven/tensorflow/java/maven/proto/com.google.protobuf-protobuf-java-3.16.3Copy head branch name to clipboard