Fix EC2 volume unit test compatibility with newer mock versions.
Use the return value of the patched ResultSet constructor directly
instead of passing a mock instance as the spec for another Mock.
This avoids InvalidSpecError when creating a Mock from an existing Mock.
--- ../tests/unit/ec2/test_volume.py	2026-10-18 01:26:08.136716224 +0300
+++ ../tests/unit/ec2/test_volume.py	2026-10-18 01:26:23.793823363 +0300
@@ -55,7 +55,7 @@
     @mock.patch("boto.resultset.ResultSet")
     def test_startElement_with_name_tagSet_calls_ResultSet(self, ResultSet, startElement):
         startElement.return_value = None
-        result_set = mock.Mock(ResultSet([("item", Tag)]))
+        result_set = ResultSet.return_value
         volume = Volume()
         volume.tags = result_set
         retval = volume.startElement("tagSet", None, None)