Use object.__hash__ for Node.__hash

This fixes a regression in commit 6029341 that
changed the `__hash__` implementation of Node from the default pointer
hash, to a hash based on the node fields.

Since these fields contains list objects, they are not hashable, making
every call to `Node.__hash__` fail.

This breaks some third-party usage such as in `django-compressor`
(See: django-compressor/django-compressor#1060)

This changed reverts the hash method back to using `object.__hash__` as
the hash implementation.

CHANGES.rst

@@ -5,6 +5,7 @@ Version 3.1.0
 
 Unreleased
 
+-   Change Node.__hash__ behavior to use object.__hash__. :issue:`1521`
 
 Version 3.0.2
 -------------

src/jinja2/nodes.py

@@ -242,7 +242,7 @@ def __eq__(self, other: t.Any) -> bool:
         return tuple(self.iter_fields()) == tuple(other.iter_fields())
 
     def __hash__(self) -> int:
-        return hash(tuple(self.iter_fields()))
+        return object.__hash__(self)
 
     def __repr__(self) -> str:
         args_str = ", ".join(f"{a}={getattr(self, a, None)!r}" for a in self.fields)

tests/test_node_hash.py

@@ -0,0 +1,4 @@
+class TestHashing:
+    def test_template_hash(self, env):
+        template = env.parse("hash test")
+        assert hash(template)