Bump `crypto-bigint` to 0.6.0-pre.5 #116

Job	Run time
build-benchmarks	2m 36s
build-wasm (1.73.0, wasm32-unknown-unknown)	17s
clippy	2m 12s
codecov	48s
build-wasm (stable, wasm32-unknown-unknown)	28s
rustfmt	4s
slow-tests (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	2m 28s
slow-tests (x86_64-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	2m 50s
tests (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	53s
tests (x86_64-unknown-linux-gnu, stable)	32s
	13m 8s

Provide feedback