I think quotes are only needed around the whole path variable
pushd "%~dp0"
FOR /F "tokens=*" %%g IN ('resolve-path.cmd') do (SET PYTHON_DIR=%%g)
-SET PATH="%PYTHON_DIR%";"%PYTHON_DIR%\Scripts";"%PATH%"
+SET PATH="%PYTHON_DIR%;%PYTHON_DIR%\Scripts;%PATH%"
popd
