[fontbe] remove workaround for old macOS bug with composites with all-zero deltas #3177

Job	Run time
Rustfmt	1m 9s
Rustfmt	1m 9s
Clippy lints	1m 36s
Clippy lints	1m 36s
cargo check no std	1m 34s
cargo check no std	1m 34s
fontbe tests	59s
fontbe tests	59s
resources/scripts/ots_test.sh	1m 17s
resources/scripts/ots_test.sh	1m 9s
fontc tests	1m 10s
fontc tests	1m 10s
tests other than fontbe,fontc	2m 11s
tests other than fontbe,fontc	2m 11s
Build GS and check the result	3m 4s
Build GS and check the result	3m 4s
cargo test fea-rs	1m 4s
cargo test fea-rs	1m 4s
cargo check wasm	1m 11s
cargo check wasm	1m 11s
	30m 22s

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