As far as I could tell, the min-version in ci.yml [was bumped](https://github.com/sfackler/rust-openssl/commit/bba1712865cc87ab1617cf03a8f79b6b0f518dcb) to 1.56 last year. Should we try to clean up old codes like this one: https://github.com/sfackler/rust-openssl/blob/8e16a8b6e28e32cedaa9eed814ba994a8c89b5e4/openssl-sys/build/main.rs#L149