Remove redundant title attribute from the "Exit Recovery Mode" link

[afercia]

Introduced in [44973].

The new "Exit Recovery Mode" link that appears in the admin toolbar when WordPress is in recovery mode has a title attribute that just repeats the visible link text (see attached screenshot).

This title attribute is pointless and just adds noise for assistive technology users. See also all the relevant tickets that removed unnecessary title attributes in the past releases: https://core.trac.wordpress.org/query?keywords=~title-attribute

As it's just a very minor change, I'd like to propose to consider this for 5.2 rather than fixing it in the next minor release.

[afercia]

In 45269:

Accessibility: Remove redundant title attribute from the "Exit Recovery Mode" link.

Fixes #47045.