Removing defunct 'encloses' definition (#3636)

Closes #3510

The definition of "Encloses" was in the draft normative text for Focus
Appearance, but was removed before publication. Therefore there is no
normative content that uses this term, and it is being removed.


<!--
    This comment and the below content is programmatically generated.
    You may add a comma-separated list of anchors you'd like a
    direct link to below (e.g. #idl-serializers, #idl-sequence):

    Don't remove this comment or modify anything below this line.
    If you don't want a preview generated for this pull request,
    just replace the whole of this comment's content by "no preview"
    and remove what's below.
-->
***
<a href="https://pr-preview.s3.amazonaws.com/w3c/wcag/pull/3636.html"
title="Last updated on May 1, 2024, 8:28 AM UTC (9b1153e)">Preview</a> |
<a
href="https://pr-preview.s3.amazonaws.com/w3c/wcag/3636/cb2b9c4...9b1153e.html"
title="Last updated on May 1, 2024, 8:28 AM UTC (9b1153e)">Diff</a>

Author: alastc

guidelines/index.html

@@ -622,8 +622,6 @@ <h1>Glossary</h1>
 
                 <dt data-include="terms/20/emergency.html" data-include-replace="true"></dt>
 
-                <dt data-include="terms/22/encloses.html" data-include-replace="true"></dt>
-
               	<dt data-include="terms/20/essential.html" data-include-replace="true"></dt>
 
                 <dt data-include="terms/20/extended-audio-description.html" data-include-replace="true"></dt>