Fields in form of WYSIWYG configuration are not accessible

WCAG warnings in the test class [org.xwiki.realtime.wysiwyg.test.ui.AllIT]:
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Check for [org.xwiki.administration.test.po.AdministrationSectionPage] at [http://xwikiweb:8080/xwiki/bin/admin/XWiki/XWikiPreferences?form_token=WT8jeGpYtBgokcxvBNFMsw&section=WYSIWYG].
Found [3] items
1: Form elements must have labels
Description: Ensures every form element has a label
Help URL: https://dequeuniversity.com/rules/axe/4.8/label?application=axeAPI
Help: Form elements must have labels
Impact: critical
Tags: cat.forms, wcag2a, wcag412, section508, section508.22.n, TTv5, TT5.c, EN-301-549, EN-9.4.1.2, ACT
HTML element: 
    <textarea data-syntax="plain/1.0" id="CKEditor.ConfigClass_0_advanced" name="CKEditor.ConfigClass_0_advanced" cols="40" rows="5" data-restricted="false">// Define changes to default configuration here. For example:
    // config.uiColor = '#AADC6E';
    // config.linkShowTargetTab = true;</textarea>
Selector: [#CKEditor\.ConfigClass_0_advanced]
Fix any of the following:
  Form element does not have an implicit (wrapped) <label>
  Form element does not have an explicit <label>
  aria-label attribute does not exist or is empty
  aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
  Element has no title attribute
  Element has no placeholder attribute
  Element's default semantics were not overridden with role="none" or role="presentation"
3: Select element must have an accessible name
Description: Ensures select element has an accessible name
Help URL: https://dequeuniversity.com/rules/axe/4.8/select-name?application=axeAPI
Help: Select element must have an accessible name
Impact: critical
Tags: cat.forms, wcag2a, wcag412, section508, section508.22.n, TTv5, TT5.c, EN-301-549, EN-9.4.1.2, ACT
HTML element: 
    <select class="form-control" multiple="">
Selector: [dd:nth-child(2) > .bootstrap-select.show-tick.bs3 > select[multiple=""]]
Fix any of the following:
  Form element does not have an implicit (wrapped) <label>
  Form element does not have an explicit <label>
  aria-label attribute does not exist or is empty
  aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
  Element has no title attribute
  Element's default semantics were not overridden with role="none" or role="presentation"
HTML element: 
    <select class="form-control" multiple="">
Selector: [dd:nth-child(4) > .bootstrap-select.show-tick.bs3 > select[multiple=""]]
Fix any of the following:
  Form element does not have an implicit (wrapped) <label>
  Form element does not have an explicit <label>
  aria-label attribute does not exist or is empty
  aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
  Element has no title attribute
  Element's default semantics were not overridden with role="none" or role="presentation"