[VARC/test] Adjust a test

This worked with the previous font it seems, but not with
the new font. Or maybe I've screwed up something...

Tests/varLib/instancer/instancer_test.py

@@ -1712,6 +1712,10 @@ class InstantiateVariableFontTest(object):
 
         location = {"0000": 0.5}
 
+        with pytest.raises(
+            NotImplementedError,
+            match="Instancing accross VarComponent axes with variation is not supported.",
+        ):
             instance = instancer.instantiateVariableFont(
                 varfont,
                 location,