🧪 TESTS: Entirely remove AiidaTestCase (#5372)

This commit converts all remaining tests that used
the (deprecated) `AiidaTestCase` unittest class,
with the equivalent pytest fixtures (such as `aiida_profile_clean`).
`AiidaTestCase` is then removed, leaving one consistent method to write tests.

.github/workflows/tests.sh

@@ -8,7 +8,6 @@ SYSTEM_TESTS="${GITHUB_WORKSPACE}/.github/system_tests"
 pytest --cov aiida --verbose --noconftest ${SYSTEM_TESTS}/test_test_manager.py
 pytest --cov aiida --verbose --noconftest ${SYSTEM_TESTS}/test_ipython_magics.py
 pytest --cov aiida --verbose --noconftest ${SYSTEM_TESTS}/test_profile_manager.py
-python ${SYSTEM_TESTS}/test_plugin_testcase.py  # uses custom unittest test runner
 
 # Until the `${SYSTEM_TESTS}/pytest` tests are moved within `tests` we have to run them separately and pass in the path to the
 # `conftest.py` explicitly, because otherwise it won't be able to find the fixtures it provides

aiida/manage/tests/__init__.py

@@ -17,15 +17,12 @@
 # pylint: disable=wildcard-import
 
 from .main import *
-from .unittest_classes import *
 
 __all__ = (
-    'PluginTestCase',
     'ProfileManager',
     'TemporaryProfileManager',
     'TestManager',
     'TestManagerError',
-    'TestRunner',
     'get_test_backend_name',
     'get_test_profile_name',
     'get_user_dict',

aiida/manage/tests/main.py

@@ -147,14 +147,16 @@ def __init__(self, profile_name):
         :param profile_name: Name of the profile to be loaded
         """
         from aiida import load_profile
-        from aiida.storage.testbase import check_if_tests_can_run
 
         self._profile = None
         try:
             self._profile = load_profile(profile_name)
         except Exception:
             raise TestManagerError(f'Unable to load test profile `{profile_name}`.')
-        check_if_tests_can_run()
+        if self._profile is None:
+            raise TestManagerError(f'Unable to load test profile `{profile_name}`.')
+        if not self._profile.is_test_profile:
+            raise TestManagerError(f'Profile `{profile_name}` is not a valid test profile.')
 
     @staticmethod
     def clear_profile():