openssl: check for conf file

Closes #34728.
[This code](https://github.com/Homebrew/homebrew/blob/885f7277bfaceb85fd2560ce3d0cedf15fb199a5/Library/Homebrew/formula_installer.rb#L123-133) is supposed to snapshot `etc` and `var` before and after a build, and then copy any new files into a special directory that is [unpacked during bottle installation](https://github.com/Homebrew/homebrew/blob/885f7277bfaceb85fd2560ce3d0cedf15fb199a5/Library/Homebrew/formula_installer.rb#L633-637).