Remove use of unbroadcast in broadcast_like

This change was introduced in 9a45333 and did not include specific tests. It was likely introduced to cope with the old restrictions regarding rewrite substitution of variables with different static broadcastable shape information, which was alleviated in #711

aesara/tensor/basic_opt.py

@@ -64,7 +64,6 @@
     stack,
     switch,
     tensor_copy,
-    unbroadcast,
     zeros,
     zeros_like,
 )
@@ -151,26 +150,8 @@ def broadcast_like(value, template, fgraph, dtype=None):
     else:
         new_shape = template.shape
     rval = alloc(value, *new_shape)
-    # the template may have 1s in its shape without being broadcastable
-    if rval.broadcastable != template.broadcastable:
-        rval = unbroadcast(
-            rval,
-            *[
-                i
-                for i in range(rval.ndim)
-                if rval.broadcastable[i] and not template.broadcastable[i]
-            ],
-        )
     assert rval.type.dtype == dtype
 
-    if rval.type.broadcastable != template.broadcastable:
-        raise AssertionError(
-            "rval.type.broadcastable is "
-            + str(rval.type.broadcastable)
-            + " but template.broadcastable is"
-            + str(template.broadcastable)
-        )
-
     return rval