chore: address deprecations caused by updating packages

[NiceAesth]

Describe your changes

RFC. This is the minimal required to get it into a working state. See: https://fastapi.tiangolo.com/advanced/events/#lifespan

Breaking changes spotted:

• https://github.com/tiangolo/fastapi/releases/tag/0.106.0
• https://github.com/tiangolo/fastapi/releases/tag/0.93.0
• https://www.starlette.io/release-notes/#0260
• https://www.starlette.io/release-notes/#0340
• https://github.com/redis/redis-py/releases/tag/v5.0.1
• akatsuki-pp-py version bump. Did we historically handle pp system versioning in some way? @cmyui

As a side effect, we now should technically support Python 3.12

Other things of note: We may support Pytest 8 soon once pytest-asyncio v23.5 is out of alpha. https://github.com/pytest-dev/pytest-asyncio/issues/737#issuecomment-1930632667 done in #571

Related Issues / Projects

Depends on #568

Checklist

• [x] I've manually tested my code

[cmyui]

+1 👍🏻