[FEATURE] t5gemma2 model support

[MVoloshin]

Hello, could you implement support for t5gemma2 model family in addition to exisiting t5gemma support, please?

[jordimas]

Hello

This is a a PR:
#2058

And wheels available:
https://github.com/OpenNMT/CTranslate2/actions/runs/26625628219#artifacts

If you can test them and provide some feedback it will be great.
Thanks

[jordimas]

Version 4.80 with T5Gemma v2 support has been released. Please open a new issue if you find any problem.