OpenSSL should be built early due to PAC bug on ARMv8

Seeing a crash building skalibs as a dependent of build-tools via adelie-base because skarnet.org uses ChaCha20-Poly1305 as its TLS cipher. There is a bug in OpenSSL's handling of Pointer Authentication in ARMv8 assembly in the version of OpenSSL shipped in the rc2 tarballs. The builder I have, an Apple M1, is therefore crashing.

See openssl/openssl@fcf6e9d056 for information on the error and the fix. I'm proposing adding system/openssl as an early-build package to ensure that further packages are built correctly on M1 and other ARMv8 chips with the PAC extension.