gh-14862: Fix tab switching when switching spaces with mouse wheel (gh-14863)

Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>

src/zen/spaces/ZenSpaceManager.mjs

@@ -649,6 +649,7 @@ class nsZenWorkspaces {
         if (Math.abs(delta) < scrollThreshold) {
           return;
         }
+        event.preventDefault();
 
         // Determine scroll direction
         let rawDirection = delta > 0 ? 1 : -1;