v0.4.2

Notable Changes

• bake: fix parsing json config with hcl v2 https://github.com/docker/buildx/pull/280
• bake: update go-cty to pull in more stdlib funcs https://github.com/docker/buildx/pull/277
• bake: ensure --builder is wired from root options https://github.com/docker/buildx/pull/321
• build: support cacheonly exporter #337
• build: improve error checking on load #281
• build: remove warning for multi-platform iidfile #351