[IR] Fix error message with remove(..., safe=True) (#1768)

Previously the node printed was incorrect.

Author: justinchuby

onnxscript/ir/_core.py

@@ -1647,12 +1647,12 @@ def _check_node_safe_to_remove(
             raise ValueError(
                 f"Node '{node!r}' is still an output of the graph and cannot be removed when safe=True."
             )
-        for use, _ in output.uses():
-            if use in to_remove:
-                continue
+        uses_not_to_remove = [user for user, _ in output.uses() if user not in to_remove]
+        if uses_not_to_remove:
             raise ValueError(
-                f"Node '{use!r}' is still being used by other nodes that are not to be "
-                f"removed. All of its uses: {list(output.uses())!r}"
+                f"Output value '{output!r}' is still being used by other nodes that are not to be "
+                f"removed. All of its users that is not being removed: {uses_not_to_remove!r}. "
+                "Please make sure these nodes are no longer using the output value."
             )