This release doesn't add any new features on top of Kobweb 0.11.3, but it now compiles against Compose for Web 1.2.2. Once you upgrade to this version, you need to also make sure your project uses Compose for Web 1.2.2 itself.
Compose for Web 1.2.2 fixed a major performance regression that caused composables to rerender unnecessarily if (at least) one of their parameters was of a type that was defined in a compose library.
See the Compose for Web 1.2.2 release notes for more information.