autodoc: Ensure type statements don't inherit docstrings (#14068)

Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>

tests/roots/test-ext-autodoc/target/pep695.py

@@ -22,6 +22,8 @@ class Foo:
 type Pep695Alias = Foo
 """This is PEP695 type alias."""
 
+type Pep695AliasUndocumented = Foo
+
 TypeAliasTypeExplicit = TypeAliasType('TypeAliasTypeExplicit', Foo)  # NoQA: UP040
 """This is an explicitly constructed typing.TypeAlias."""
 

tests/test_ext_autodoc/test_ext_autodoc.py

@@ -2292,6 +2292,12 @@ def test_autodoc_pep695_type_alias() -> None:
         '   This is PEP695 type alias of PEP695 alias.',
         '',
         '',
+        # Undocumented alias should not inherit any documentation
+        '.. py:type:: Pep695AliasUndocumented',
+        '   :module: target.pep695',
+        '   :canonical: ~target.pep695.Foo',
+        '',
+        '',
         '.. py:type:: Pep695AliasUnion',
         '   :module: target.pep695',
         '   :canonical: str | int',