message: Use `keyboard::ModifiersChanged` in `PaneGrid`
diff: @@ -539,10 +539,8 @@ where
  }
  }
  }
  -
  - *self.pressed_modifiers = modifiers;
  }
  - keyboard::Event::KeyReleased { modifiers, .. } => {
  + keyboard::Event::ModifiersChanged(modifiers) => {
  *self.pressed_modifiers = modifiers;
  }
  _ => {}
  