Fix `deprecated_in_future` lint #779

Job	Run time
doc	17s
msrv	53s
check format	15s
check	16s
semver-checks	2m 27s
check (--no-default-features)	14s
test	54s
check (--no-default-features --features use_alloc)	13s
check (--all-targets --all-features)	25s
All checks succeeded	1s
	5m 55s

Provide feedback