chore: direnv explicitly uses python3 layout (#559)

Author: lamchau

.envrc

@@ -1,3 +1,3 @@
 export VIRTUAL_ENV=venv
-layout python
-python -c 'import pyparsing' 2> /dev/null || pip install -r scripts/requirements.txt
+layout python python3
+python -c 'import pyparsing' 2>/dev/null || pip install -r scripts/requirements.txt