Remove deprecated "distributions" package from exports.

It has been deprecated since 2019, and is now triggering warnings on
TensorFlow startup.  It does, however, still need to be included in
`python/__init__.py` so that it can be found by `tf.compat.v1.distributions`,
which several projects depend on.

We will remove the entire package from TensorFlow as a follow-up.  But
at the moment, doing so would break too many other projects.

PiperOrigin-RevId: 558816905

tensorflow/python/__init__.py

@@ -48,3 +48,7 @@ _exported_dunders = set([
 # Expose symbols minus dunders, unless they are allowlisted above.
 # This is necessary to export our dunders.
 __all__ = [s for s in dir() if s in _exported_dunders or not s.startswith('_')]
+
+# TODO(b/296442875): remove this when we remove the tf.distribution package.
+# This import is needed for tf.compat.v1.distributions.
+from tensorflow.python.ops.distributions import distributions

tensorflow/python/modules_with_exports.py

@@ -116,7 +116,6 @@ from tensorflow.python.ops import rnn_cell
 from tensorflow.python.ops import sets
 from tensorflow.python.ops import stateful_random_ops
 from tensorflow.python.ops import while_v2
-from tensorflow.python.ops.distributions import distributions
 from tensorflow.python.ops.linalg import linalg
 from tensorflow.python.ops.linalg.sparse import sparse
 from tensorflow.python.ops.losses import losses