systemdMinimal: expose `withRepart` flag and disable it

systemd-repart relies on cryptsetup to perform LUKS operations,
therefore, it's not suitable for systemdMinimal.

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

···
 , withCompression ? true  # adds bzip2, lz4, xz and zstd
 , withCoredump ? true
 , withCryptsetup ? true
+, withRepart ? true
 , withDocumentation ? true
 , withEfi ? stdenv.hostPlatform.isEfi
 , withFido2 ? true
···
 assert withHomed -> withCryptsetup;
 assert withHomed -> withPam;
 assert withUkify -> withEfi;
+assert withRepart -> withCryptsetup;
 
 let
   wantCurl = withRemote || withImportd;
···
     "-Dlibidn2=${lib.boolToString withLibidn2}"
     "-Dfirstboot=${lib.boolToString withFirstboot}"
     "-Dsysusers=${lib.boolToString withSysusers}"
+    "-Drepart=${lib.boolToString withRepart}"
     "-Dquotacheck=false"
     "-Dldconfig=false"
     "-Dsmack=true"

pkgs/top-level/all-packages.nix

···
     withCompression = false;
     withCoredump = false;
     withCryptsetup = false;
+    withRepart = false;
     withDocumentation = false;
     withEfi = false;
     withFido2 = false;