Convert from Webpack to Vite (#34450)

Co-authored-by: Renaud Chaput <renchap@gmail.com>

app/javascript/mastodon/common.ts

@@ -0,0 +1,9 @@
+import Rails from '@rails/ujs';
+
+export function start() {
+  try {
+    Rails.start();
+  } catch {
+    // If called twice
+  }
+}