[JsonEncoder] Add missing changelog entries

Author: mtarld

src/Symfony/Component/JsonEncoder/CHANGELOG.md

@@ -6,4 +6,5 @@ CHANGELOG
 
  * Introduce the component as experimental
  * Add native PHP lazy ghost support
+ * Remove `JsonEncoder::$forceEncodeChunks`, `JsonDecoder::$forceEncodeChunks`, and `EncoderDecoderCacheWarmer::$forceEncodeChunks`
  * Allow to select the warmup of object and list in `JsonEncodable` and `json_encoder.encodable`