Don’t apply external icon treatment to links with no href

fixes #3645

Author: dragonstyle

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

@@ -590,7 +590,7 @@ window.document.addEventListener("DOMContentLoaded", function (event) {
         return filterRegex.test(href) || localhostRegex.test(href);
     }
     // Inspect non-navigation links and adorn them if external
- 	var links = window.document.querySelectorAll('a:not(.nav-link):not(.navbar-brand):not(.toc-action):not(.sidebar-link):not(.sidebar-item-toggle):not(.pagination-link):not(.no-external):not([aria-hidden]):not(.dropdown-item)');
+ 	var links = window.document.querySelectorAll('a[href]:not(.nav-link):not(.navbar-brand):not(.toc-action):not(.sidebar-link):not(.sidebar-item-toggle):not(.pagination-link):not(.no-external):not([aria-hidden]):not(.dropdown-item)');
     for (var i=0; i<links.length; i++) {
       const link = links[i];
       if (!isInternal(link.href)) {