Preparing for OP-TEE 4.9.0

[BCC all OP-TEE maintainers]

Hi OP-TEE maintainers & contributors,

OP-TEE version 4.9.0 is now scheduled for release on 2026-01-16. So, now is a good time to start testing the master branch across various platforms and report or fix any bugs.

The GitHub pull request for collecting Tested-by tags or any other comments is https://github.com/OP-TEE/optee_os/pull/7666.

I have now created the 4.9.0-rc1 tags in the various OP-TEE gits. Please proceed with the testing.

You can find more information related to releases here: https://optee.readthedocs.io/en/latest/general/releases.html

Thanks, Jens