Cleanup: correct API usage for script access

In practice this didn't cause problems, but accessing scripts via
bpy.utils.resource_path('USER') ignores the BLENDER_USER_SCRIPTS
environment variable.

tests/python/bl_load_py_modules.py

@@ -42,7 +42,7 @@ if not bpy.app.build_options.xr_openxr:
     BLACKLIST.add("viewport_vr_preview")
 
 BLACKLIST_DIRS = (
-    os.path.join(bpy.utils.resource_path('USER'), "scripts"),
+    os.path.join(bpy.utils.user_resource('SCRIPTS')),
 ) + tuple(addon_utils.paths()[1:])