Automate the release incrementation on main

[frouioui]

Feature Description

When we create the first release candidate of a major release, we need to increment the major release count on main in those files:

• go/vt/servenv/version.go
• java/client/pom.xml
• java/example/pom.xml
• java/grpc-client/pom.xml
• java/jdbc/pom.xml
• java/pom.xml

This incrementation should be automated as part of the make do_release command. The automation will increment the release number, create a commit and invite us to open a pull request against main.

Here are two pull requests that to reflect the changes that need to be automated:

• Incrementing to release 12.0.0-SNAPSHOT #8419
• Incrementing to release 13.0.0-SNAPSHOT #9066