Add `auto_shrink()` function to `egui::Window` #11797

Job	Run time
android	34s
Check wasm32 + wasm-bindgen	3m 43s
Format + check + test	6m 12s
cargo-deny aarch64-apple-darwin	43s
Check Windows	2m 34s
cargo-deny aarch64-linux-android	40s
cargo-deny i686-pc-windows-gnu	48s
cargo-deny i686-pc-windows-msvc	38s
cargo-deny i686-unknown-linux-gnu	39s
cargo-deny wasm32-unknown-unknown	38s
cargo-deny x86_64-apple-darwin	38s
cargo-deny x86_64-pc-windows-gnu	42s
cargo-deny x86_64-pc-windows-msvc	38s
cargo-deny x86_64-unknown-linux-gnu	39s
cargo-deny x86_64-unknown-linux-musl	39s
cargo-deny x86_64-unknown-redox	40s
	21m 5s

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