systemd: add withUtmp flag and inherit in passthru

The NixOS systemd module has to include some upstream unit files
depending on if the systemd package was built with utmp support.
This makes it possible for the NixOS systemd module to detect if the
systemd package was built with utmp support.

pkgs/os-specific/linux/systemd/default.nix

@@ -100,6 +100,7 @@
 , withTimesyncd ? true
 , withTpm2Tss ? !stdenv.hostPlatform.isMusl
 , withUserDb ? !stdenv.hostPlatform.isMusl
+, withUtmp ? !stdenv.hostPlatform.isMusl
   # tests assume too much system access for them to be feasible for us right now
 , withTests ? false
 
@@ -502,9 +503,10 @@ stdenv.mkDerivation {
     "-Dbpf-framework=true"
   ] ++ lib.optionals withTpm2Tss [
     "-Dtpm2=true"
+  ] ++ lib.optionals (!withUtmp) [
+    "-Dutmp=false"
   ] ++ lib.optionals stdenv.hostPlatform.isMusl [
     "-Dgshadow=false"
-    "-Dutmp=false"
     "-Didn=false"
   ];
   preConfigure =
@@ -683,7 +685,7 @@ stdenv.mkDerivation {
     # runtime; otherwise we can't and we need to reboot.
     interfaceVersion = 2;
 
-    inherit withCryptsetup withHostnamed withImportd withLocaled withMachined withTimedated util-linux kmod kbd;
+    inherit withCryptsetup withHostnamed withImportd withLocaled withMachined withTimedated withUtmp util-linux kmod kbd;
 
     tests = {
       inherit (nixosTests) switchTest;