Remove skrifa from vello's public API #1946

Job	Run time
formatting	25s
cargo check (msrv) (wasm32)	35s
cargo check (msrv) (windows-latest)	2m 0s
cargo check (aarch64-android)	24s
cargo check (msrv) (macos-latest)	46s
cargo clippy (windows-latest)	2m 35s
cargo check (msrv) (ubuntu-latest)	44s
cargo clippy (macos-latest)	1m 26s
cargo clippy (wasm32)	1m 11s
Prime LFS Cache	6s
cargo clippy (ubuntu-latest)	1m 41s
cargo test (wasm32)	24s
cargo doc	25s
typos	7s
cargo test (windows-latest)	2m 30s
cargo test (macos-latest)	1m 20s
cargo test (ubuntu-latest)	2m 52s
	19m 31s

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