Update version to v1.6.0 #50

Job	Run time
clippy (aws-lc-rs, --features bindgen,unstable)	1m 4s
apidiff (aws-lc-sys, branch)	2m 6s
clippy (aws-lc-rs, --features bindgen,unstable,fips)	1m 25s
mirai-analysis	2m 46s
apidiff (aws-lc-sys, published)	2m 13s
dependency-review	23s
apidiff (aws-lc-fips-sys, branch)	2m 41s
rustfmt	31s
apidiff (aws-lc-fips-sys, published)	2m 35s
udeps	7m 47s
apidiff (aws-lc-rs, branch)	2m 9s
apidiff (aws-lc-rs, published)	2m 15s
copyright	8s
Resolve the dependencies to the minimum SemVer version	37s
Minimum Supported Rust Version	5m 8s
semver-checks	3m 47s
	37m 35s

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