diff --git a/docs/_templates/layout.html b/docs/_templates/layout.html
index b8138bdfd2..b971964990 100644
--- a/docs/_templates/layout.html
+++ b/docs/_templates/layout.html
@@ -92,22 +92,24 @@
 
 {% block footer %}
     {{ super() }}
-    <template data-promotion-banner data-clear-duration="90" data-date-until="2024-06-22">
+    <template data-promotion-banner="" data-clear-duration="90" data-date-until="2024-06-22">
         <div class="promotion-banner">
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+            <svg aria-hidden="true" viewBox="0 0 190 132" width="36" height="36"><defs><path id="a" d="M89.58 26.597C81.876 11.063 65.8.375 47.213.375S12.552 11.063 4.85 26.597C1.746 32.857 0 39.902 0 47.354c0 6.875 1.484 13.404 4.15 19.288 12.926 1.555 27.562 2.432 43.064 2.432 15.503 0 30.138-.877 43.064-2.432 2.667-5.884 4.152-12.413 4.152-19.288 0-7.452-1.747-14.497-4.85-20.757"/></defs><g fill="none" fill-rule="evenodd"><g><g><path fill="#DFDFDF" d="M49.467 127.165h4.465V86.51h-4.465"/><path fill="#DFDFDF" d="M55.836 127.153c0 2.677-2.18 4.847-4.87 4.847s-4.87-2.17-4.87-4.847c0-2.676 2.18-4.846 4.87-4.846s4.87 2.17 4.87 4.846M134.91 127.165h4.466V86.51h-4.465"/><path fill="#DFDFDF" d="M142.404 127.153c0 2.677-2.18 4.847-4.87 4.847s-4.87-2.17-4.87-4.847c0-2.676 2.18-4.846 4.87-4.846s4.87 2.17 4.87 4.846"/><path fill="#D23C2B" d="M94.975 86.13L0 70.85s2.768 30.56 94.975 30.56c92.208 0 94.976-30.56 94.976-30.56L94.976 86.13"/><path fill="#DE4D33" d="M189.95 69.77c0 12.38-42.52 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+            {# We use ``&#x2013;`` instead of ``&ndash;`` for XHTML compatibility when building ePub #}
+            {# https://github.com/sphinx-doc/sphinx/pull/12386 #}
             <a href="https://nl.wagtail.space/">
                 <div>
                     <strong>Wagtail Space NL</strong>
-                    <br>12 &ndash; 14 June 2024 in Arnhem, The Netherlands
+                    <br />12 &#x2013; 14 June 2024 in Arnhem, The Netherlands
                 </div>
             </a>
             <a href="https://us.wagtail.space/">
                 <div>
                     <strong>Wagtail Space US</strong>
-                    <br>20 &ndash; 22 June 2024 in Philadelphia, USA
+                    <br />20 &#x2013; 22 June 2024 in Philadelphia, USA
                 </div>
             </a>
-            <button class="close" aria-label="Hide banner" aria-expanded="true" type="button" data-clear>&#x2715;</button>
+            <button class="close" aria-label="Hide banner" aria-expanded="true" type="button" data-clear="">&#x2715;</button>
         </div>
     </template>
 {% endblock %}