Local upload provider does not create uploads directory

[ethanwu10]

Describe the bug
If the local upload provider's uploadDirectory does not exist, it is not automatically created on startup and causes a WARN-level log from fastify-static complaining that the root does not exist.

To Reproduce
Steps to reproduce the behavior:

1. Use uploads/local upload provider
2. Ensure that the uploads directory does not exist
3. Start rCTF

Expected behavior
No warning is logged, the directory should be created.