Allow different versions for differently signed RoT images (#5580)

Currently we restrict all RoT archives for {Gimlet, PSC, Sidecar} to be
the same version. This restricts us to having staging and production
images to be the same version. What we actually want is all archives for
a particular kind _signed with the same key_ to have the same version.

tufaceous-lib/src/assemble/manifest.rs

@@ -294,11 +294,14 @@ impl<'a> FakeDataAttributes<'a> {
             KnownArtifactKind::SwitchRot => "fake-sidecar-rot",
         };
 
+        // For our purposes sign = board represents what we want for the RoT
+        // and we don't care about the SP at this point
         let caboose = CabooseBuilder::default()
             .git_commit("this-is-fake-data")
             .board(board)
             .version(self.version.to_string())
             .name(self.name)
+            .sign(board)
             .build();
 
         let mut builder = HubrisArchiveBuilder::with_fake_image();