Add note about `cargo update` to the raw-window-handle changelog update
# 0.26.0 (2021-12-01)
-- Update `raw-window-handle` to `v0.4`. This is _not_ a breaking change, we still implement `HasRawWindowHandle` from `v0.3`, see [rust-windowing/raw-window-handle#74](https://github.com/rust-windowing/raw-window-handle/pull/74).
+- Update `raw-window-handle` to `v0.4`. This is _not_ a breaking change, we still implement `HasRawWindowHandle` from `v0.3`, see [rust-windowing/raw-window-handle#74](https://github.com/rust-windowing/raw-window-handle/pull/74). Note that you might have to run `cargo update -p raw-window-handle` after upgrading.
- On X11, bump `mio` to 0.8.
- On Android, fixed `WindowExtAndroid::config` initially returning an empty `Configuration`.
- On Android, fixed `Window::scale_factor` and `MonitorHandle::scale_factor` initially always returning 1.0.
