Revert "renderer/metal: free resources when occluded"

This reverts commit b5d543705d.

src/renderer/Thread.zig

@@ -250,9 +250,6 @@ fn drainMailbox(self: *Thread) !void {
                 // Set our visible state
                 self.flags.visible = v;
 
-                // Set it on the renderer
-                try self.renderer.setVisible(v);
-
                 // If we became visible then we immediately trigger a draw.
                 // We don't need to update frame data because that should
                 // still be happening.