Update changelog

Signed-off-by: mulhern <amulhern@redhat.com>

Author: mulkieran

CHANGES.txt

@@ -1,3 +1,13 @@
+devicemapper 0.33.6 (UNRELEASED)
+================================
+Recommended Rust toolchain version: 1.70.0
+Lowest supported Rust toolchain version: 1.69.0
+Recommended development release: Fedora 38
+
+- Tidies and Maintenance:
+  https://github.com/stratis-storage/devicemapper-rs/pull/864
+
+
 devicemapper 0.33.5
 ===================
 Recommended Rust toolchain version: 1.70.0