WIP: Test for Psycopg3 fix

[szokeasaurusrex]

Draft PR containing a test for #3111. In order to implement this change, we first would need to modify our test suite to allow running tests against both psycopg2 and 3. For testing purposes, this change modifies our test suite to only run against psycopg3; we would undo this change before merging

The main challenge preventing this change from working is an error occurring during test teardown. The test itself passes; the teardown error is the only problem. The test also tests the feature as intended: if we undo the change from #3111, the test fails.

Adding transaction=True to the Pytest-Django decorator eliminates the teardown error allowing the test to pass; however, if we undo #3111, the test still passes, indicating that running with transaction=True does not properly test the functionality we wish to verify.

Resolves #3139