examples/cbor: keep newlib nano disabled in the example

CBOR parsing fails with newlib nano configuration, observed on ESP32-C2.

Closes IDFCI-1375

examples/protocols/cbor/main/cbor_example_main.c

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
 /* CBOR Example
 
    This example code is in the Public Domain (or CC0 licensed, at your option.)