aria-label should not be used on <time>

[Alec Rust]

As-per MDN docs:

The aria-label attribute is NOT supported in code, (..) and time

The aria-label attribute is intended for interactive elements only. When placed on non-interactive elements, such as those listed above, it may not be read or may confuse your users as a non-interactive element that acts like an interactive one.

This causes some errors with accessibility tools that check <time> doesn't have aria-label. Looks like this gem adds aria-label, but it should probably be something like data-label instead.

Looks like this was added here to improve accessibility, but I don't think it's doing that. <time> element is all the description that is needed.

[Jose Farias]

You're right, thanks for calling this out! #140