[3.11] gh-115274: Fix direct invocation of testmock/testpatch.py (GH-115275)

[sobolevn]

(cherry picked from commit f8e9c57)

Co-authored-by: Nikita Sobolev [email protected]

• Issue: Direct invocation of Lib/test/test_unittest/testmock/testpatch.py fails #115274

[sobolevn]

Local run:

» ./python.exe Lib/unittest/test/testmock/testpatch.py
..............................................................................................................
----------------------------------------------------------------------
Ran 110 tests in 0.100s

OK