fix CI builds · oppi.li/at-advent@d23d44a

··· 8 8 - cargo 9 9 - rustc 10 10 - rustfmt 11 + - openssl 11 12 12 13 steps: 13 14 - name: build 14 15 command: | 16 + export PKG_CONFIG_PATH="${PKG_CONFIG_PATH:+$PKG_CONFIG_PATH:}$(nix build nixpkgs#openssl.dev --no-link --print-out-paths)/lib/pkgconfig" 15 17 cargo build --all 16 18