Update RELEASE-NOTES

Author: irfano

RELEASE-NOTES.txt

@@ -14,6 +14,7 @@
 - [*][Internal] Migrated legacy Material Icons to Material Symbols [https://github.com/woocommerce/woocommerce-android/pull/15081]
 - [*] Fix widget sizing issues and improve refresh rate upon switching site or logging out [https://github.com/woocommerce/woocommerce-android/pull/15127]
 - [*] Unified transition animations across screens [https://github.com/woocommerce/woocommerce-android/pull/15128]
+- [*] Fixed a rare NullPointerException crash on the Dashboard screen [https://github.com/woocommerce/woocommerce-android/pull/15138]
 
 23.8
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