chore(ci): enforce compliance with cargo fmt (#2467)

Author: TomAFrench

flake.nix

@@ -238,6 +238,13 @@
           cargoArtifacts = native-cargo-artifacts;
         });
 
+        cargo-fmt = craneLib.cargoFmt (nativeArgs // {
+          inherit GIT_COMMIT GIT_DIRTY;
+
+          cargoArtifacts = native-cargo-artifacts;
+          doCheck = true;
+        });
+
         cargo-test = craneLib.cargoTest (nativeArgs // (testArgs 8000) // {
           inherit GIT_COMMIT GIT_DIRTY;