light/dark toggle fire resize event

fixes sizing issues in plotly-python and heatmaply
fixes non-displaying leaflet

this is a backport to v1.7; changelog there

Author: gordonwoodhull

src/resources/formats/html/templates/quarto-html-before-body.ejs

@@ -186,6 +186,7 @@
       toggleColorMode(toAlternate);
       setStyleSentinel(toAlternate);
       toggleGiscusIfUsed(toAlternate, darkModeDefault);
+      window.dispatchEvent(new Event('resize'));
     };
 
     <% if (respectUserColorScheme) { %>