* Replace swish with silu
* revert nn.silu to nn.swish due to older version
* simplify optimized silu conditional and fix format
* Update activations.py
* Update activations_tf.py
* Update modeling_flax_utils.py
* Update modeling_openai.py
* add swish testcase
* add pytorch swish testcase
* Add more robust python version check
* more formatting fixes
Co-authored-by: TFUsers <TFUsers@gmail.com>