Fixed #33628 -- Ignored directories with empty names in autoreloader check for template changes.

Regression in 68357b2ca9.

tests/template_tests/test_autoreloader.py

@@ -81,6 +81,17 @@ class TemplateReloadTests(SimpleTestCase):
         autoreload.reset_loaders()
         self.assertEqual(mock_reset.call_count, 2)
 
+    @override_settings(
+        TEMPLATES=[
+            {
+                "DIRS": [""],
+                "BACKEND": "django.template.backends.django.DjangoTemplates",
+            }
+        ]
+    )
+    def test_template_dirs_ignore_empty_path(self):
+        self.assertEqual(autoreload.get_template_directories(), set())
+
     @override_settings(
         TEMPLATES=[
             {