Add internal release note

Author: RafaelKayumov

RELEASE-NOTES.txt

@@ -6,6 +6,7 @@
 - [internal] Improved login flow during Jetpack Setup for accounts using emails marked as suspicious [https://github.com/woocommerce/woocommerce-ios/pull/15491]
 - [internal] Update Sentry to 8.46.0 to allow building with Xcode 16.3 [https://github.com/woocommerce/woocommerce-ios/pull/15503]
 - [*] Product Form: Fixed an issue where a draft variable product cannot be published [https://github.com/woocommerce/woocommerce-ios/pull/15513]
+- [internal] Fixed the issue where some product thumbnails appeared blurry [https://github.com/woocommerce/woocommerce-ios/pull/15517]
 
 22.1
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