Fix nightly container builds

Our nightly container builds are failing, because all the integration tests are skipped
(since we don't have faiss/feast on the containers). pytest returns error code '5'
in this case, causing us to fail the container.

Use the workaround as suggested pytest-dev/pytest#2393 (comment)

tests/conftest.py

@@ -22,3 +22,9 @@
 import pytest
 
 REPO_ROOT = Path(__file__).parent.parent
+
+
+def pytest_sessionfinish(session, exitstatus):
+    # if all the tests are skipped, lets not fail the entire CI run
+    if exitstatus == 5:
+        session.exitstatus = 0