fix(core): a11y fix on mobile DropdownNavbarItem (#10898)

Author: mxschmitt

packages/docusaurus-theme-classic/src/theme/NavbarItem/DropdownNavbarItem/index.tsx

@@ -151,6 +151,10 @@ function DropdownNavbarItemMobile({
           'menu__link menu__link--sublist menu__link--sublist-caret',
           className,
         )}
+        // # hash permits to make the <a> tag focusable in case no link target
+        // See https://github.com/facebook/docusaurus/pull/6003
+        // There's probably a better solution though...
+        href={props.to ? undefined : '#'}
         {...props}
         onClick={(e) => {
           e.preventDefault();