Adds Python 3.11 to tests, by: Filip, Piotr

Author: caseneuve

pythonanywhere/api/base.py

@@ -7,6 +7,7 @@
     "3.8": "python38",
     "3.9": "python39",
     "3.10": "python310",
+    "3.11": "python311",
 }