Close Temporary file handles in tests

[markreidvfx]

I noticed these file handles were leaking when running tests on mingw64.
I matched the style that's in the files, but I think it would be better to use a TemporaryDirectory and cleanup when the test is done. Some tests are doing that, but it is a bit mixed.

[codecov-commenter]

Codecov Report

Merging #1363 (7359ac7) into main (8847e90) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1363   +/-   ##
=======================================
  Coverage   86.27%   86.27%           
=======================================
  Files         196      196           
  Lines       19865    19871    +6     
  Branches     2309     2309           
=======================================
+ Hits        17138    17144    +6     
  Misses       2161     2161           
  Partials      566      566           

Flag	Coverage Δ
py-unittests	86.27% <100.00%> (+<0.01%)	⬆️

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Impacted Files	Coverage Δ
tests/test_otiod.py	96.92% <100.00%> (+0.14%)	⬆️
tests/test_otioz.py	98.01% <100.00%> (+0.06%)	⬆️

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[jminor]

This looks like a good step forward to me. I always find Python's scoping rules for file handles confusing, and in this case the code really just wants a unique filename, not an actual file handle. Is there a standard pattern for cleaning up temp files in unit tests that we should be using here?

[markreidvfx]

Currently some tests use unittest.TestCase setUp and tearDown methods

    def setUp(self):
        self.tmpDir = tempfile.mkdtemp()

    def tearDown(self):
        shutil.rmtree(self.tmpDir)

Some tests are using tempfile.TemporaryDirectory

with tempfile.TemporaryDirectory() as temp_dir:
    temp_file = os.path.join(temp_dir, "test_basic.otio")

Some tests are not cleaning up at all.

In pyaaf2 I write all test results to known location instead of temp. I also don't delete them so you can inspect them if a failure happens.

[JeanChristopheMorinPerso]

In pyaaf2 I write all test results to known location instead of temp. I also don't delete them so you can inspect them if a failure happens.

If we were using Pytest (and here not just as a runner), we would get all these features. But that's for another day.

[jminor]

There is some other discussion about using pytest here: #1364

I'm fine accepting this PR as-is, and then we can look into the improvements that pytest could give us as a separate change.