* egui_demo_app: remove wgpu and pollster as direct dependencies
* eframe: use same web-sys version as wgpu crate
* Make note that web_sys_unstable_apis is required by the wgpu crate
* Rename the glow web painter in eframe
* Remove trait DummyWebGLConstructor from web_glow_painter.rs
* cargo fmt
* Fix check.sh
Since https://github.com/emilk/egui/pull/1919 we can continue
the application after closing the native window. It therefore makes
more sense to call `frame.close()` to close the native window,
instead of `frame.quit()`.
