Update CHANGELOG.md

Author: BenjaminKazemi

CHANGELOG.md

@@ -6,8 +6,6 @@
 ### Features
 
 * Add minimal and medium thinking levels. ([a7c0ed8](https://github.com/googleapis/go-genai/commit/a7c0ed8b1fcade06ffcc62a91344e36e56d17f37))
-* Add minimal and medium thinking levels. ([71c18bd](https://github.com/googleapis/go-genai/commit/71c18bdae60b28df28c3f99e9a6f983c13d162aa))
-* Add minimal and medium thinking levels. ([a48566d](https://github.com/googleapis/go-genai/commit/a48566dc952f78d9f40c33cfa459f7d876e3199f))
 * Add ultra high resolution to the media resolution in Parts. ([47b89eb](https://github.com/googleapis/go-genai/commit/47b89ebb0cb9531bd440afb15df14a9668142f72))
 * ephemeral token support in go ([7515bbe](https://github.com/googleapis/go-genai/commit/7515bbef37d86ac0d695c11d81c31a42cb330e7e))
 * support multi speaker for Vertex AI ([457541d](https://github.com/googleapis/go-genai/commit/457541d1839e37fe7bd588462ecb42b670a1ec1c))