php80Extensions.openssl: pin to openssl_1_1

pkgs/top-level/php-packages.nix

···
 , net-snmp
 , oniguruma
 , openldap
+, openssl_1_1
 , openssl
 , pam
 , pcre2
···
         }
         {
           name = "openssl";
-          buildInputs = [ openssl ];
+          buildInputs = if (lib.versionAtLeast php.version "8.1") then [ openssl ] else [ openssl_1_1 ];
           configureFlags = [ "--with-openssl" ];
           doCheck = false;
         }