[fast-snapshot] use antlir2 to build dnf confs

Summary:
This will be much more up to date than being stuck on the ROU version that was
in the last antlir1 snapshot which is usually several days old, sometimes more
than a week.

Test Plan: Preview of generated changes in D46974266

Reviewed By: r1mikey

Differential Revision: D46974076

fbshipit-source-id: 9eb51a587817e970cec0d492633172c481437768

antlir/antlir2/antlir2_compile/src/rpms.rs

@@ -120,7 +120,7 @@ pub(crate) enum Reason {
     Clean,
     Dependency,
     Group,
-    Unkown,
+    Unknown,
     User,
     WeakDependency,
 }