Fix building of lints

Signed-off-by: Marcel Müller <neikos@neikos.email>

flake.nix

@@ -84,6 +84,10 @@
             pname = "dashmap-ref";
             cargoExtraArgs = "-p dashmap-ref";
             src = fileSetForCrate ./lints/dashmap-ref;
+
+            postFixup = ''
+              mv $out/lib/libdashmap_ref{.so,@$RUSTUP_TOOLCHAIN.so}
+            '';
           }
         );