Merge "Remove use of removeprefix" into unmaintained/yoga

Author: Zuul

nova/tests/unit/console/test_websocketproxy.py

@@ -637,7 +637,9 @@ def test_reject_open_redirect(self, url='//example.com/%2F..'):
         # now the same url but with extra leading '/' characters removed.
         if expected_cpython in errmsg:
             location = result[3].decode()
-            location = location.removeprefix('Location: ').rstrip('\r\n')
+            if location.startswith('Location: '):
+                location = location[len('Location: '):]
+            location = location.rstrip('\r\n')
             self.assertTrue(
                 location.startswith('/example.com/%2F..'),
                 msg='Redirect location is not the expected sanitized URL',