test: add draft20220-12 tests

tests/selfvalidate_test.cxx

@@ -172,6 +172,8 @@ INSTANTIATE_TEST_SUITE_P(Draft6, JsonSchema, SchemaTests(Version::Draft06), Sche
 INSTANTIATE_TEST_SUITE_P(Draft7, JsonSchema, SchemaTests(Version::Draft07), SchemaTestName);
 INSTANTIATE_TEST_SUITE_P(Draft2019_09, JsonSchema, SchemaTests(Version::Draft2019_09),
                          SchemaTestName);
+INSTANTIATE_TEST_SUITE_P(Draft2020_12, JsonSchema, SchemaTests(Version::Draft2020_12),
+                         SchemaTestName);
 
 int main(int argc, char ** argv) {
   testing::InitGoogleMock(&argc, argv);