chore: ease signed integer restriction on high bit-widths

tests/mlir/test_graph_converter.py

@@ -426,23 +426,6 @@ Subgraphs:
         %5 = astype(%4, dtype=int_)        # EncryptedScalar<uint1>
         return %5
 
-            """,  # noqa: E501
-        ),
-        pytest.param(
-            lambda x: x - 300,
-            {"x": "encrypted"},
-            range(200),
-            RuntimeError,
-            """
-
-Function you are trying to compile cannot be converted to MLIR:
-
-%0 = x                       # EncryptedScalar<uint8>
-%1 = 300                     # ClearScalar<uint9>
-%2 = subtract(%0, %1)        # EncryptedScalar<int10>
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ signed values are only supported on circuits with up to 8-bit integers
-return %2
-
             """,  # noqa: E501
         ),
     ],