docs: prevent caching version embed

docs/assets/versions.js

@@ -1,22 +1,26 @@
-function callback(response) {
-    const div = document.createElement('div');
-    div.innerHTML = response.html;
-    document.body.appendChild(div);
-    const container = div.querySelector('.rst-versions');
-    div.querySelector('.rst-current-version').addEventListener('click', function() {
-        const classes = container.className.split(' ');
-        const index = classes.indexOf('shift-up');
-        if (index === -1) {
-            classes.push('shift-up');
-        } else {
-            classes.splice(index, 1);
-        }
-        container.className = classes.join(' ');
-    });
-}
+(function() {
+    const callbackName = 'callback_' + new Date().getTime();
+    window[callbackName] = function (response) {
+        const div = document.createElement('div');
+        div.innerHTML = response.html;
+        document.body.appendChild(div);
+        const container = div.querySelector('.rst-versions');
+        div.querySelector('.rst-current-version').addEventListener('click', function() {
+            const classes = container.className.split(' ');
+            const index = classes.indexOf('shift-up');
+            if (index === -1) {
+                classes.push('shift-up');
+            } else {
+                classes.splice(index, 1);
+            }
+            container.className = classes.join(' ');
+        });
+    }
+
+    var script = document.createElement('script');
+    script.src = 'https://argocd-notifications.readthedocs.io/_/api/v2/footer_html/?'+
+        'callback=' + callbackName + '&project=argocd-notifications&page=&theme=mkdocs&format=jsonp&docroot=docs&source_suffix=.md&version=' + (window['READTHEDOCS_DATA'] || { version: 'latest' }).version;
+
+    document.getElementsByTagName('head')[0].appendChild(script); 
+})();
 
-var script = document.createElement('script');
-script.src = 'https://argocd-notifications.readthedocs.io/_/api/v2/footer_html/?'+
-    'callback=callback&project=argocd-notifications&page=&theme=mkdocs&format=jsonp&docroot=docs&source_suffix=.md&version=' + (window['READTHEDOCS_DATA'] || { version: 'latest' }).version;
-
-document.getElementsByTagName('head')[0].appendChild(script);