fix: include targetingKey in flagd serialized evaluation context (#58)

Signed-off-by: Federico Bond <federicobond@gmail.com>

providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py

@@ -193,6 +193,7 @@ def _convert_context(self, evaluation_context: EvaluationContext):
         s = Struct()
         if evaluation_context:
             try:
+                s["targetingKey"] = evaluation_context.targeting_key
                 s.update(evaluation_context.attributes)
             except ValueError as exc:
                 message = (