quartus-prime-lite: use exec to avoid one needless process

pkgs/applications/editors/quartus-prime/default.nix

···
                 echo "export NIXPKGS_IS_QUESTA_WRAPPER=1" >> "$wrapped"
                 ;;
         esac
-        echo "$wrapper $prog \"\$@\"" >> "$wrapped"
+        echo "exec $wrapper $prog \"\$@\"" >> "$wrapped"
     done
 
     cd $out