refactor(client/router): drop redundant download attribute filter

`event.downloadRequest != null` already catches links with a `download`
attribute (including `download=""`), so the `sourceElement.hasAttribute('download')`
check was dead. Keep the `target` check — `target="_self"` and named
targets still fire the navigate event in the current window and should
not be intercepted.

Author: brc-dd

src/client/app/router/navigationApi.ts

@@ -93,14 +93,15 @@ export const createNavigationApiRouterStrategy: RouterStrategyFactory = (
     const src = event.sourceElement
     // Mirror the legacy click-handler filters when the navigation was
     // element-initiated (e.g. link click). Programmatic navigations have a
-    // null sourceElement and are always considered eligible.
+    // null sourceElement and are always considered eligible. `download` is
+    // handled by `event.downloadRequest` above.
     if (src) {
       if (src.closest('.vp-raw')) return
       // covers docsearch action buttons and button-wrapped link content
       if (src.closest('button') || src.querySelector('button')) return
       if (
         (src instanceof HTMLAnchorElement || src instanceof SVGAElement) &&
-        (src.hasAttribute('download') || src.hasAttribute('target'))
+        src.hasAttribute('target')
       ) {
         return
       }