Update changelog

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

Author: mulkieran

CHANGES.txt

@@ -1,3 +1,17 @@
+libcryptsetup-rs 0.12.1
+=======================
+Recommended Rust toolchain version: 1.85.0
+Recommended development environment: Fedora 40
+
+- Tidies and Maintenance:
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/405
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/404
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/403
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/402
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/400
+  https://github.com/stratis-storage/libcryptsetup-rs/pull/398
+
+
 libcryptsetup-rs 0.12.0
 =======================
 Recommended Rust toolchain version: 1.84.0