Motivation
We're doing shenanigans at the moment as per #22, where we run the pre-commit from a venv.

There are only select circumstances where the workaround is strictly necessary - e.g. deptry and even if that case we might want to provide the non-venv way for people who prefer to do an explicit mapping (we can just have different defaults) Maybe an --in-venv option to force it to use a install based process.

Another reason to use the venv approach is for the sake of editor integrations, e.g. ruff to keep versions in sync when we need to have the tool installed both in the venv and run locally. Relates to #111.

Summary of desired enhancement
Provide a way to add pre-commits in the conventional way