feat: add support for secp256r1 and replace libsecp256k1

CHANGELOG.md

@@ -5,12 +5,17 @@ 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 the versioning scheme outlined in the [README.md](README.md).
 
-## Unreleased
+## [Unreleased]
+
+### Added
+
+- Added support for new Clarity 4 builtin, `secp256r1-verify?` (not activated until epoch 3.3)
 
 ### Changed
 
 - Renamed Clarity 4's new `block-time` to `stacks-block-time`
 - Improve cost-tracking for type-checking function arguments in epoch 3.3 (see [#6425](https://github.com/stacks-network/stacks-core/issues/6425))
+- Replaced `libsecp256k1` with `k256` and `p256` from RustCrypto and removed separate Wasm implementations.
 
 ## [3.2.0.0.2]