VED-457: fix backoff error2

Author: Akol125

e2e/test_create_immunization.py

@@ -42,7 +42,7 @@ def test_non_unique_identifier(self):
         imms["id"] = imms_id  # Imms fhir resource should include the id for update
         etag_version = int(res.headers.get("E-Tag", 1))
         print("E-Tag being sent:", etag_version)
-        print("Update payload:", json.dumps(imms, indent=2))
+        print("Update payload:", json.dumps(imms, indent=2, default=str))
         self.default_imms_api.update_immunization(imms_id, imms, headers={"E-Tag": str(etag_version)})
         self.assertEqual(res.status_code, 200)
         del imms["id"]  # Imms fhir resource should not include an id for create