Bugfix: cannot tab into dropdowns in Safari

[KoolADE85]

This PR fixes an issue where users could not tab into a dropdown using Safari with default settings. Tab presses would skip past all dropdowns, and, when open, tabs would skip past all dropdown options too.

Now, tab keys behave consistently in Safari as with other browsers.

#3673

Contributor Checklist

• I have run the tests locally and they passed. (refer to testing section in contributing)
• I have added tests, or extended existing tests, to cover any new features or bugs fixed in this PR

optionals

• I have added entry in the CHANGELOG.md

[github-actions]

Thank you for your contribution to Dash! 🎉

[camdecoster]

@m6ti would you be able to check out this branch and see if it addresses the issue that you brought up (#3673)?

[m6ti]

Tested this locally with the short python script in #3673 and it fixes the issue 🎉

[T4rk1n]

💃