[setup.py] pin ufo2ft <3 in view of upcoming major change

setup.py

@@ -33,7 +33,7 @@
     "fontMath": ">=0.9.3",
     "fonttools": ">=4.47.2",
     "glyphsLib": ">=6.6.0",
-    "ufo2ft": ">=2.33.4",
+    "ufo2ft": ">=2.33.4,<3",
     "ufoLib2": ">=0.16.0",
 }