Set types.Union as an alias for types.UnionType.

This is required because some Sphinx versions used the old name from a prerelease Python version.

Author: domdfcoding

sphinx_jinja2_compat/__init__.py

@@ -27,6 +27,7 @@
 #
 
 # stdlib
+import sys
 from typing import Any, Callable, List, TypeVar
 
 __all__: List[str] = []
@@ -67,5 +68,8 @@ def environmentfilter(f: F) -> F:
 	def contextfunction(f: F) -> F:
 		return jinja2.utils.pass_context(f)
 
-	jinja2.utils.contextfunction = contextfunction  # type: ignore[attr-defined]
-	jinja2.contextfunction = contextfunction  # type: ignore[attr-defined]
+# This all has to be up here so it's triggered first.
+if sys.version_info >= (3, 10):
+	# stdlib
+	import types
+	types.Union = types.UnionType