Cleanup usage of unsafe blocks #783

Job	Run time
apidiff (aws-lc-sys, branch)	2m 25s
bindgen-dependency (ubuntu-latest)	29s
apidiff (aws-lc-sys, published)	2m 37s
bindgen-dependency (macos-12)	34s
bindgen-fips-dependency (ubuntu-latest)	19s
apidiff (aws-lc-fips-sys, branch)	2m 36s
bindgen-dependency (macos-13-xlarge)	24s
apidiff (aws-lc-fips-sys, published)	2m 49s
bindgen-fips-dependency (macos-12)	38s
bindgen-dependency (windows-latest)	56s
apidiff (aws-lc-rs, branch)	2m 24s
clippy (aws-lc-rs, --features bindgen,unstable)	1m 20s
bindgen-fips-dependency (macos-13-xlarge)	28s
clippy (aws-lc-rs, --features bindgen,unstable,fips)	1m 39s
apidiff (aws-lc-rs, published)	2m 44s
bindgen-fips-dependency (windows-latest)	40s
copyright	3s
clippy (aws-lc-rs, --no-default-features --features aws-lc-sys)	34s
dependency-review	21s
metadata-checks	30s
mirai-analysis	3m 3s
Resolve the dependencies to the minimum SemVer version	42s
rustfmt	23s
semver-checks	1m 10s
udeps	7m 39s
	37m 27s

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