fix: remove duplicate allOf and maxItems entries in draft2020-12 KNOWN set

Signed-off-by: Sagar Choudhary <sagar6203620715@gmail.com>

Author: Sagar-6203620715

bin/jsonschema_suite

@@ -281,7 +281,6 @@ class SanityTests(unittest.TestCase):
                 "$vocabulary",
                 "additionalProperties",
                 "allOf",
-                "allOf",
                 "anyOf",
                 "const",
                 "contains",
@@ -301,7 +300,6 @@ class SanityTests(unittest.TestCase):
                 "items",
                 "maxContains",
                 "maxItems",
-                "maxItems",
                 "maxLength",
                 "maxProperties",
                 "maximum",