add .direnv to default exclude argument

[fpgmaas]

PR Checklist

• A description of the changes is added to the description of this PR.
• If there is a related issue, make sure it is linked to this PR.
• If you've fixed a bug or added code that should be tested, add tests!
• Documentation in docs is updated

Description of changes

[mkniewallner]

The default list of excludes makes me think that we could benefit from ignoring all files that are in .gitignore, similarly to what black does.

If you think that it makes sense, I'd be happy to create an issue for it.

[fpgmaas]

The default list of excludes makes me think that we could benefit from ignoring all files that are in .gitignore, similarly to what black does.

If you think that it makes sense, I'd be happy to create an issue for it.

@mkniewallner That definitely makes sense :) Would have also prevented the related issue from popping up indeed.