Add deprecation stub for aesara.tensor.nnet.opt

aesara/tensor/nnet/opt.py

+import warnings
+
+
+warnings.warn(
+    "The module `aesara.tensor.nnet.opt` is deprecated; use `aesara.tensor.nnet.rewriting` instead.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+from aesara.tensor.nnet.rewriting import *  # noqa: F401 E402 F403