Fix the permission error in Wave tour containerized version when run as a nonroot user

[sulhicader]

Wave SDK Version, OS

Error come from v1.5.1

Actual behavior

ERROR: Traceback (most recent call last):
File "/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 693, in lifespan async with self.lifespan_context(app) as maybe_state:
File "/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 569, in aenter await self._router.startup()
File "/app/venv/lib/python3.10/site-packages/starlette/routing.py", line 670, in startup await handler()
File "/app/examples/tour.py", line 374, in on_startup os.mkdir(tour_tmp_dir) PermissionError: [Errno 13] Permission denied: '/app/examples/_tour_apps_tmp' ERROR: Application startup failed.

Expected behavior

Should be able to open the app without permission error.

Steps To Reproduce

1. Do this
2. Do that
3. Do something else
4. See error