Cleanup EVP_PKEY serialization #1315

Job	Run time
apidiff (aws-lc-sys, branch)	2m 54s
apidiff (aws-lc-sys, published)	3m 36s
apidiff (aws-lc-fips-sys, branch)	3m 15s
apidiff (aws-lc-fips-sys, published)	3m 49s
apidiff (aws-lc-rs, branch)	2m 47s
bindgen-dependency (ubuntu-latest)	25s
apidiff (aws-lc-rs, published)	2m 59s
bindgen-fips-dependency (ubuntu-latest)	21s
bindgen-dependency (macos-13)	39s
bindgen-fips-dependency (macos-13)	35s
bindgen-dependency (macos-14-xlarge)	30s
bindgen-dependency (windows-latest)	51s
clippy (aws-lc-rs, --features bindgen,unstable)	1m 21s
bindgen-fips-dependency (macos-14-xlarge)	26s
clippy (aws-lc-rs, --features bindgen,unstable,fips)	1m 52s
bindgen-fips-dependency (windows-latest)	1m 20s
clippy (aws-lc-rs, --no-default-features --features aws-lc-sys)	48s
dependency-review	16s
Resolve the dependencies to the minimum SemVer version (aws-lc-rs)	51s
rustfmt	28s
semver-checks	1m 21s
udeps	7m 53s
Resolve the dependencies to the minimum SemVer version (aws-lc-sys)	40s
Resolve the dependencies to the minimum SemVer version (aws-lc-fips-sys)	1m 17s
metadata-checks	31s
	41m 45s

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