overlay/kernel-builder: use modules_install as a install target when kernel is modular
@@ -409,6 +409,7 @@ stdenv.mkDerivation (inputArgs // {
installTargets =
if isCompressed != false then [ "zinstall" ] else [ "install" ]
++ installTargets
+ ++ optional isModular "modules_install"
;
preInstall = optionalString enableCombiningBuildAndInstallQuirk ''
