cms: remove `alloc` feature (#1566) #1530

Job	Run time
build (1.81.0, thumbv7em-none-eabi)	24s
build (1.81.0, wasm32-unknown-unknown)	28s
build (stable, thumbv7em-none-eabi)	21s
build (stable, wasm32-unknown-unknown)	23s
minimal-versions	0s
test (1.81.0)	1m 22s
test (stable)	1m 15s
	4m 13s

Provide feedback