LLVM 17.x Release Branch created

Hi everyone! I am glad to announce that the LLVM 17.x release process is starting with the creation of the release branch.

The next step is that 17.0.0-rc1 will be tagged and released Friday 28th of July.

You can help with the release by filing issues in the 17.x release milestone.

If you have any questions about the LLVM release process, please see the documentation and my EuroLLVM keynote on YouTube.