Fixed variable warning.

Author: michaelstaib

src/HotChocolate/AspNetCore/src/AspNetCore.Authorization/DefaultAuthorizationHandler.cs

@@ -45,6 +45,8 @@ public DefaultAuthorizationHandler(
             throw new ArgumentNullException(nameof(authorizationPolicyCache));
 #if NET7_0_OR_GREATER
         _canCachePolicies = _authorizationPolicyProvider.AllowsCachingPolicies;
+#else
+        _canCachePolicies = true;
 #endif
     }