Enable accesskit feature in egui_demo_app #1

Job	Run time
android	22s
Check wasm32 + wasm-bindgen	33s
cargo-deny aarch64-apple-darwin	28s
Format + check + test	56s
cargo-deny aarch64-linux-android	30s
Check Windows	32s
cargo-deny i686-pc-windows-gnu	46s
cargo-deny i686-pc-windows-msvc	32s
cargo-deny i686-unknown-linux-gnu	27s
cargo-deny wasm32-unknown-unknown	29s
cargo-deny x86_64-apple-darwin	29s
cargo-deny x86_64-pc-windows-gnu	28s
cargo-deny x86_64-pc-windows-msvc	27s
cargo-deny x86_64-unknown-linux-gnu	30s
cargo-deny x86_64-unknown-linux-musl	41s
cargo-deny x86_64-unknown-redox	31s
	8m 41s

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