fix($sanitize): dont not remove tab index property

[chirag04]

fixes #5853

[mary-poppins]

Thanks for the PR! Please check the items below to help us merge this faster. See the contributing docs for more information.

• Uses the issue template (#8371)

If you need to make changes to your pull request, you can update the commit with git commit --amend.
Then, update the pull request with git push -f.

Thanks again for your help!

[Narretz]

Hi, thanks for the PR; while it's a very simple change it's better to put your changes on a separate branch, and rebase that branch on master to stay up to date. When you merge the master, you create these merge commits and add unrelated commits which makes it harder to review.

[caitp]

I wouldn't worry about it, it's trivial to just pick the commit we want from here when checking it in.

Should include a simple test case, as well --- no need to test anything functional, just make sure that the attribute doesn't get discarded

[chirag04]

@caitp @Narretz Should i create a new branch with a testcase for it?

[caitp]

@chirag04 don't worry about creating a new branch, you can simply amend this last commit with a test case, when we land this we'll only take the last commit since the first one has already been fixed seperately

[caitp]

In the future though, you should put all your fixes and features into branches, so that you don't accidentally overwrite them =)

[lgalfaso]

landed as 799353c