Testing: Treat warnings as errors rucio#5522

There are multiple Warnings (like `DeprecationWarning`s,
`PendingDeprecationWarning`s, `SAWarning`s, ...) in our project. This commit
resolves them.

lib/rucio/tests/conftest.py

@@ -16,6 +16,7 @@
 from __future__ import print_function
 
 import traceback
+import warnings
 
 import pytest
 
@@ -368,3 +369,8 @@ def metrics_mock():
             mock.patch('rucio.core.monitor.TIMINGS', new={}), \
             mock.patch('prometheus_client.values.ValueClass', new=values.MutexValue):
         yield registry
+
+
+@pytest.fixture(autouse=True)
+def treat_warnings_as_exceptions():
+    warnings.filterwarnings("error")