cms: remove `alloc` feature #1528

Job	Run time
minimal-versions	0s
test (1.81.0)	1m 18s
build (1.81.0, thumbv7em-none-eabi)	23s
test (stable)	1m 12s
build (1.81.0, wasm32-unknown-unknown)	24s
build (stable, thumbv7em-none-eabi)	16s
build (stable, wasm32-unknown-unknown)	19s
	3m 52s

Provide feedback