Fix hassfest by removing knx from forbidden package file exceptions (home-assistant#170561)

Author: silamon

script/hassfest/requirements.py

@@ -306,8 +306,6 @@
     },
     # https://github.com/basnijholt/aiokef
     "kef": {"homeassistant": {"aiokef"}},
-    # https://github.com/danifus/pyzipper
-    "knx": {"xknxproject": {"pyzipper"}},
     # https://github.com/hthiery/python-lacrosse
     "lacrosse": {"homeassistant": {"pylacrosse"}},
     # ???