Filter header element root has tabindex which messes up tabbing through filter inputs

[Fralleee]

What version of React-Table are you using?

Version 6.7.5

What bug are you experiencing, or what feature are you proposing?

If I have multiple column filters and I try tabbing between them there's a gap in each where the header-element gets focus. Header element has tabindex:

<div class="rt-th" role="button" tabindex="0">
  <input type="text" value="" style="width: 100%;">
</div>

[Fralleee]

Pull request: #619 seems to have created this issue
This commit (f74ba3c) added tabindex and role of button to fix linting errors, however these props should not apply to filter headers since it creates extra tabindexes between the inputs.