- Use frozen dependencies with hashes to ensure reproducible dependency
installation in a secure way.
- Uses `uv` and pre-commit to automatically generate the locked
requirements files from pyproject.toml.
- While the translation dependencies can be installed directly with
`uv`, uv doesn’t seem to be able to add `--find-link=…` to the exported
`requirements/translate.txt`, for that reason the translation
dependencies are left as they are and won’t be automatically exported
via pre-commit.
- So whenever `uv lock —upgrade` is run, it will freeze the latest patch
versions.
- The production dependencies are specified with a `~` which means `>=`
at the last digit of requirements.
- The dev dependencies have `>=` to make them easy to update, if
something breaks in dev either fix it or go back to the old frozen
dependencies.
- Moved generated dependencies in requirements/ folder.
- Use `--no-deps` where applicable while installing these generated
requirements as the sub-dependencies are already resolved.

This builds on the #4134 PR that initially introduced machine
translations into Hypha. This isolates the translation behavior; putting
pip dependencies in a separate `requirements-translate.txt` and will not
attempt any translate imports unless the setting for it is true.

Other small changes are also a full docs page explaining how to install
language packages & changing the setting once again from
`SUBMISSION_TRANSLATIONS_ENABLED` to `APPLICATION_TRANSLATIONS_ENABLED`
to reflect the system wide shift away from submission terminology.