chore: fix changelog

Author: sandhose

CHANGELOG.md

@@ -14,13 +14,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - *(deps)* update wasmtime requirement from >=22, <35 to >=22, <36
 - fix clippy warnings
 - bump rust/clippy to 1.88.0
-# Changelog
-All notable changes to this project will be documented in this file.
-
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
-and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
-
-## [Unreleased]
 
 ## [0.1.6](https://github.com/matrix-org/rust-opa-wasm/compare/v0.1.5...v0.1.6) - 2025-07-21