Fix: Mark repo model properties for security and analysis as optional

Despite the JSON schema doesn't mention the properties are optional it
seems they are actually optional. The property `advanced_security` is
missing in several of our responses and therefore we got a model error.

pontos/github/models/organization.py

@@ -272,9 +272,9 @@ class SecurityAndAnalysis(GitHubModel):
             Protection is used
     """
 
-    advanced_security: SecurityAndAnalysisType
-    secret_scanning: SecurityAndAnalysisType
-    secret_scanning_push_protection: SecurityAndAnalysisType
+    advanced_security: Optional[SecurityAndAnalysisType] = None
+    secret_scanning: Optional[SecurityAndAnalysisType] = None
+    secret_scanning_push_protection: Optional[SecurityAndAnalysisType] = None
 
 
 @dataclass