Add meta_data workaround to 23.4 release notes

Author: joshheald

RELEASE-NOTES.txt

@@ -1,6 +1,10 @@
 *** PLEASE FOLLOW THIS FORMAT: [<priority indicator, more stars = higher priority>] <description> [<PR URL>]
 *** Use [*****] to indicate smoke tests of all critical flows should be run on the final IPA before release (e.g. major library or OS update).
 
+23.4
+-----
+- [*] Workaround to make custom field decoding more reliable with sites which return incorrectly formatted meta_data for products, variations, and orders. [https://github.com/woocommerce/woocommerce-ios/pull/16141]
+
 23.3
 -----
 - [*] Order details: Display only physical items in the Shipping Labels section. [https://github.com/woocommerce/woocommerce-ios/pull/16127]