Always ignore template at top level pre-commit

[paddyroddy]

We lint at the top level, and at the template level. It doesn't really make sense to template both, and some of the hooks get confused with the cookiecutter templating. Previously, we were ignoring some, but actually makes sense to ignore it all.

The downside is that locally it will be annoying to lint at the package level. But that is fine because CI with lint at the template level. Sometimes you may need to create a dummy project to fix the issue.

[dstansby]

So I understand, on one of the CI runs we still template a new package and run pre-commit on that new package? If so I think this is a nice simplification 👍

[matt-graham]

From experience in working on both #318 and #319 the occasional bad interactions between templating syntax and what pre-commit hooks expect in the various files are a bit of pain so this seems a good idea to me.

[samcunliffe]

Yeah, agreed.