inrease animation timeout; disable animation for fab

app/lib/features/geckoview/features/browser/presentation/screens/browser.dart

@@ -187,8 +187,8 @@ class _TabBar extends HookConsumerWidget {
     );
 
     return AnimatedSize(
-      duration: const Duration(milliseconds: 125),
-      curve: Curves.easeInOut,
+      duration: const Duration(milliseconds: 250),
+      curve: Curves.easeInOutQuart,
       child: Visibility(
         visible:
             sheetController.value != null ||

app/lib/features/geckoview/features/browser/presentation/widgets/browser_modules/browser_fab.dart

@@ -67,13 +67,6 @@ class BrowserFab extends HookConsumerWidget {
       child = const SizedBox.shrink(key: ValueKey('no_fab'));
     }
 
-    return AnimatedSwitcher(
-      key: child.key,
-      duration: const Duration(milliseconds: 200),
-      transitionBuilder: (child, animation) {
-        return ScaleTransition(scale: animation, child: child);
-      },
-      child: child,
-    );
+    return child;
   }
 }