Add `--binary` when creating patch for unstaged files

[GrahamBorland]

This fixes the pre-commit hook to cope with unstaged binary files. Without this option, the hook fails when there is an unstaged binary file.

error: cannot apply binary patch to 'some/binary/file' without full index line
error: some/binary/file: patch does not apply

[JLLeitschuh]

Sorry it's taken so long to get back to you on this. I'm happy to merge this, but I need an entry in the changelog file. After that, more than happy to merge this!

[GrahamBorland]

Changelog entry added, thanks!

[JLLeitschuh]

Looks like CI is failing for this PR. Can you take a look?

[JLLeitschuh]

Once CI is passing, I'm more than happy to merge this 😃