[🛠️] Fix-whisper-breaking-changes 
# What does this PR do?
Should fix the backward compatibility issue with `model.config.forced_decoder_ids = ...` and should help users who want to generate with timestamps. 

Fixes #21937 and #21878
_The documentation is not available anymore as the PR was closed or merged._<|||||>Test are failing because we do not check the `model.config` updating and will look good! <|||||>The same should now be applied to both the `TF` and the `Flax` version as the overwriting of the `generate` function is also supported. Will open a follow up PR for these <|||||>For TF and flax #21334