const-oid: add v0.9.4 to CHANGELOG.md

Backport of RustCrypto#1114

Author: baloo

const-oid/CHANGELOG.md

@@ -4,6 +4,12 @@ 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).
 
+## 0.9.4 (2023-07-10)
+### Added
+- rfc8894 (SCEP) OIDs. ([#1114])
+
+[#1114]: https://github.com/RustCrypto/formats/pull/1114
+
 ## 0.9.3 (2023-06-29)
 ### Added
 - `Database::find_names_for_oid` ([#1129])