[3.14] gh-141865: Fix translation of strings in changes.py extension (GH-141882) (#141883)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

Author: miss-islington

Doc/tools/templates/dummy.html

@@ -27,8 +27,8 @@
 
 In extensions/changes.py:
 
-{% trans %}Deprecated since version {deprecated}, will be removed in version {removed}{% endtrans %}
-{% trans %}Deprecated since version {deprecated}, removed in version {removed}{% endtrans %}
+{% trans %}Deprecated since version %s, will be removed in version %s{% endtrans %}
+{% trans %}Deprecated since version %s, removed in version %s{% endtrans %}
 
 In docsbuild-scripts, when rewriting indexsidebar.html with actual versions: