Use a patch version of reveal-chalkboard plugin

this is an unreleased version with a fix for Reveal.js 5.0.3 change regarding overlay styling

configuration

@@ -37,7 +37,9 @@ export TIPPY_JS=6.3.7
 export PDF_JS=2.8.335
 export REVEAL_JS=5.1.0
 export REVEAL_JS_MENU=2.1.0
-export REVEAL_JS_CHALKBOARD=4.2.5
+# unrelease version needed for a fix with Reveal.js 5
+# https://github.com/rajgoel/reveal.js-plugins/pull/180
+export REVEAL_JS_CHALKBOARD=8408d5a265abf74a042122520bbb4fd0d31feaed
 export REVEAL_JS_PDFEXPORT=2.0.1
 export LIST_JS=2.3.1
 export DAY_JS=1.11.7

package/src/common/update-html-dependencies.ts

@@ -386,7 +386,7 @@ export async function updateHtmlDependencies(config: Configuration) {
       );
       return Promise.resolve();
     },
-    false, // not a commit
+    true, // true if commit, false otherwise
     false, // no v prefix,
   );
 

src/resources/formats/revealjs/plugins/chalkboard/plugin.js

@@ -443,6 +443,7 @@ const initChalkboard = function ( Reveal ) {
 			container.style.opacity = 1;
 			container.style.visibility = 'visible';
 			container.style.pointerEvents = 'none';
+			container.style['backdrop-filter'] = 'none';
 
 			var slides = document.querySelector( '.slides' );
 			var aspectRatio = Reveal.getConfig().width / Reveal.getConfig().height;