Address failing sp-repo-review checks

[ukmo-ccbunney]

📰 Custom Issue

Following a QA refresh of this repo, the following Scientific Python Repo Review errors are being generated (and are currently being ignored in pyproject.toml):

### Tasks
- [ ] `PY007` Supports an easy task runner (nox or tox)
- [ ] `PP309"` Filter warnings specified
- [ ] `PC170` Uses PyGrep hooks (only needed if rST present)

These should be addressed and removed from this ignore list if possible.