chore: changelog entry solo action 15.0

Signed-off-by: exploreriii <[email protected]>

Author: exploreriii

CHANGELOG.md

@@ -29,6 +29,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - docs: Add `docs/sdk_developers/project_structure.md` to explain repository layout and import paths.
 
 ### Changed
+- chore: bumped solo action from 14.0 to 15.0 (#764)
 - chore: replaced hardcoded 'testnet' messages with environment network name
 - chore: validate that token airdrop transactions require an available token service on the channel (#632) 
 - chore: update local environment configuration in env.example (#649)