bcrypt-pbkdf: scrypt: bump cipher to `0.5.0-pre.4` #889

Job	Run time
build (1.72.0, thumbv7em-none-eabi)	17s
build (1.72.0, wasm32-unknown-unknown)	28s
test (1.72.0)	39s
build (stable, thumbv7em-none-eabi)	22s
build (stable, wasm32-unknown-unknown)	41s
test (stable)	43s
minimal-versions / minimal-versions	1m 50s
	5m 0s

Provide feedback