Sphinx 5.0+ prints double colons for roles

[xqt]

Describe the bug

For examle:
:1: Foo
is renderend as
1: Foo
with Sphinx 4.5
https://doc.wikimedia.org/pywikibot/stable/library_usage.html

whereas Sphinx 5.0+ renders
1:: Foo

https://doc.wikimedia.org/pywikibot/master/library_usage.html

How to Reproduce

Other examples with variables and parameters
Sphinx 4.5 (single quotes after Variables, Parameters, Return type) like:
Variables: summary_key - Edit summary message key
https://doc.wikimedia.org/pywikibot/stable/scripts_ref/scripts.html#module-scripts.basic

Sphinx 5.02 (doible quotes after Variables, Parameters, Return type) like:
Variables:: summary_key - Edit summary message key
https://doc.wikimedia.org/pywikibot/master/scripts_ref/scripts.html#module-scripts.basic

Expected behavior

Single quotes are expected as in Sphinx 4.5

Your project

See "Show Source" of the given links above.

Screenshots

Sphinx 4.5

Sphinx 5.0.2

OS

Linux

Python version

Python 3.7

Sphinx version

4.5.0 vs. 5.0.2

Sphinx extensions

'sphinx.ext.autodoc', 'sphinx.ext.autosectionlabel', 'sphinx.ext.extlinks', 'sphinx.ext.todo', 'sphinx.ext.viewcode', 'sphinx.ext.autosummary', 'sphinx.ext.napoleon',

Extra tools

No response

Additional context

No response

[jfbu]

This is not a Sphinx change per se, I can reproduce it with Sphinx 4.2.0, but is impacted by Docutils 0.18.

Try pip install docutils==0.17.1.

Minimal example:

Welcome to FOO's documentation!
===============================

test
----

:1: hello

:2: world

[jfbu]

From Docutils 0.18 release notes:

Write footnote brackets and field term colons to HTML, so that they are present also without CSS and when copying text.

Our basic.css does

dl.field-list > dt:after {
    content: ":";
}

but there is already since DocUtils 0.18 a <span class="colon">:</span>.

Adding

dl.field-list  .colon {
    display: none;
}

to basic.css appears to fix the problem in a way which should not depend on Docutils version. Assuming a colon class was not used by extensions etc....

ping @AA-Turner for advice. Is there a potential issue with footnote brackets? I have not followed episodes of Sphinx compatibitility patches for Docutils 0.18.

[AA-Turner]

Fixed by #10595

A