Add keras.ops.rot90 for tf.image.rot90

[innat]

tf api: https://www.tensorflow.org/api_docs/python/tf/image/rot90
torch api: https://pytorch.org/docs/stable/generated/torch.rot90.html
jax api: https://jax.readthedocs.io/en/latest/_autosummary/jax.numpy.rot90.html

In keras, it provides RandomRotation and probably not replacable with tf.image.90.

[fchollet]

It is a numpy op: https://numpy.org/doc/stable/reference/generated/numpy.rot90.html

Any op that is in numpy is in-scope for inclusion in Keras. Since there are already built-in functions for it in all backends, adding it should be easy. Are you able to open a PR?

[innat]

I'm working on a related topic and can submit a PR if that helps.

[fchollet]

Please do.