Migrating to latest aiida: pydantic 2, graphene 3

[eimrek]

In order to make this project work with AiiDA 2.5+, this pr migrates to

• pydantic 2
• fastapi 0.115.5 (previous version was not comptaibly with pydantic 2)
• starlette.graphql (which was removed from starlette/fastapi) was replaced with starlette-graphene3
• and as a result, graphene 2 also needed to be migrated to graphene 3

In the process of these migrations, the following things were changed:

• tests that start aiida processes needed to be set as async and use an async test client, otherwise there was an event-loop conflict with aiida;
• the upload file endpoint was not working with the previous approach, and now uses Fastapi's upload file that can handle large files in a manner that doesn't need to load it fully into memory.

Fixes #70

[agoscinski]

Went through it with @eimrek. For some changes it is not very clear why they were needed, but it works and it follows FastAPI guidelines (specifically the async client). Also the create_upload_file has to be adapted in the future to directly stream the byte string, but with that needs more work most likely on the aiida-core side. So it looks fine, merging it to make more progress on the endpoints!

Since we change the linter and formatter in the next PR we ignore failing pre-commit in the CI. RTD failure we fix in a future branch