Fix python gh action paths

Author: forus

.github/workflows/validate-python.yml

@@ -17,8 +17,8 @@ jobs:
           docker run -v ${PWD}:/cbioportal-core python:3.6 /bin/sh -c '
             cd cbioportal-core &&
             pip install -r requirements.txt &&
-            export PYTHONPATH=/cbioportal-core/src/main/resources/scripts &&
-            cd src/test/scripts/ &&
+            export PYTHONPATH=/cbioportal-core/scripts &&
+            cd tests/ &&
             python unit_tests_validate_data.py &&
             python system_tests_validate_data.py &&
             python system_tests_validate_studies.py'