gh-92886: Fixing tests that fail when running with optimizations (-O) in test_zipimport.py

[jackh-ncl]

#92886

Before:

$ ./python.exe -Om unittest test.test_zipimport 

................F...................s............F...................s...
======================================================================
FAIL: testDefaultOptimizationLevel (test.test_zipimport.CompressedZipImportTestCase.testDefaultOptimizationLevel)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/.../dev/cpython/Lib/test/test_zipimport.py", line 657, in testDefaultOptimizationLevel
    self.assertRaises(AssertionError, mod.test, False)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: AssertionError not raised by test

======================================================================
FAIL: testDefaultOptimizationLevel (test.test_zipimport.UncompressedZipImportTestCase.testDefaultOptimizationLevel)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/.../dev/cpython/Lib/test/test_zipimport.py", line 657, in testDefaultOptimizationLevel
    self.assertRaises(AssertionError, mod.test, False)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: AssertionError not raised by test

----------------------------------------------------------------------
Ran 73 tests in 0.073s

FAILED (failures=2, skipped=2)

After:

./python.exe -Om unittest test.test_zipimport

....................................s................................s...
----------------------------------------------------------------------
Ran 73 tests in 0.065s

OK (skipped=2)