Page history tab radio buttons have no label

WCAG warnings in the test class [org.xwiki.administration.test.ui.AllIT]:

Validation in the test method [testImportWithHistoryWhenNoPage]
Check for [org.xwiki.flamingo.skin.test.po.AttachmentsViewPage] at http://xwikiweb:8080/xwiki/bin/view/Main/TestPage#History.
Found [1] items

1: Form elements must have labels
Description: Ensures every form element has a label
Help URL: https://dequeuniversity.com/rules/axe/4.6/label?application=axeAPI
Help: Form elements must have labels
Impact: critical
Tags: cat.forms, wcag2a, wcag412, section508, section508.22.n, ACT

HTML element: 
    <input type="radio" name="rev1" id="rev1_3.1" value="3.1">
Selector: rev1_3\.1
Fix all of the following:
  Form element has explicit <label> that is hidden

HTML element: 
    <input type="radio" name="rev2" id="rev2_3.1" value="3.1" checked="checked">
Selector: rev2_3\.1
Fix all of the following:
  Form element has explicit <label> that is hidden

[...]

The issue is reported for all the radio buttons.