Replace problematic symbol in idf_component.yml

Fixes #2131

Author: bblanchon

idf_component.yml

@@ -1,7 +1,7 @@
 version: "7.2.0"
 description: >-
   A simple and efficient JSON library for embedded C++.
-  ⭐ 6690 stars on GitHub!
+  ★ 6690 stars on GitHub!
   Supports serialization, deserialization, MessagePack, streams, filtering, and more.
   Fully tested and documented.
 url: https://arduinojson.org/