Fix: Delete trailing semicolon in BRB::bundle()

Normally this would be a compilation error, but Bevy has an
`impl Bundle for ()` somewhere.

The intended bundle content gets discarded and a unit is implicitly
returned. That unit is implicitly converted into a `Bundle`, satisfying
the compiler.

src/widgets/mod.rs

@@ -120,7 +120,7 @@ impl BigRedButton {
         TextColor(WHITE.into()),
         TextShadow::default(),
       ],
-    );
+    )
   }
 
   /// Re-color the button when a pointer passes over it