added GPTNeoForTokenClassification (#22908)
* added GPTNeoForTokenClassification
* add to top-level init
* fixup
* test
* more fixup
* add to gpt_neo.mdx
* repo consistency
* dummy copy
* fix copies
* optax >= 0.1.5 assumes jax.Array exists - which it doesn't for jax <= 0.3.6
* merge with main made this superfluous
* added classifier_dropout
* remove legacy code
* removed fmt:on/off
removed expected_outputs
* doc style fix
* classifier_dropout is always in config
---------
Co-authored-by: Prof. Peter Schneider-Kamp <jps@ordbogen.com>