Fix misplaced label tag in icon links component

[vkbo]

Replace the <label> tag with <span> in icon-links.html, and add aria-hidden="true" to the icon itself.

Closes #1287

@trallard @drammock

[vkbo]

The failing CI-jobs seem to be completely unrelated to this PR, so I'm not doing anything about it unless you want me to:

=== Sphinx Warnings test ===

Checking build warnings in file: "D:\a\pydata-sphinx-theme\pydata-sphinx-theme\warnings.txt" and comparing to expected warnings defined in "D:\a\pydata-sphinx-theme\pydata-sphinx-theme\tests\warning_list.txt"


Unexpected warning: C:\hostedtoolcache\windows\Python\3.11.3\x64\Lib\site-packages\pandas\core\frame.py:docstring of pandas.core.frame.DataFrame.drop:1: WARNING: undefined label: 'advanced.shown_levels'

[choldgraf]

Looks good to me - thanks for this improvement. I agree the CI tests aren't related and can be fixed elsewhere.

Just to double-check, you confirmed that we don't use label. as a selector for these elements in our CSS? We should make sure that this re-name won't break any CSS or JS selectors. If not then I'm +1. Approving under the assumption this has already been done!

[vkbo]

Not that I could find anyway. All usage of label in the CSS seems to be related to the sidebars.