Merge pull request #265023 from trofi/postfix-build-in-parallel

postfix: enable parallel builds

pkgs/servers/mail/postfix/default.nix

···
     make makefiles CCARGS='${ccargs}' AUXLIBS='${auxlibs}'
   '';
 
+  enableParallelBuilding = true;
+
   NIX_LDFLAGS = lib.optionalString withLDAP "-llber";
 
   installTargets = [ "non-interactive-package" ];