tutor/changelog.d/20230818_112124_kyle_buildkit.md

• [Deprecation] The template variable is_buildkit_enabled, which now always returns True, is deprecated. Plugin authors should assume BuildKit is enabled and remove the variable from their templates (by @kdmccormick).
• 💥[Deprecation] Tutor no longer supports the legacy Docker builder, which was previously available by setting DOCKER_BUILDKIT=0 in the host environment. Going forward, Tutor will always use BuildKit (a.k.a. docker buildx in Docker v19-v22, or just docker build in Docker v23). This transition will improve build performance and should be seamless for Tutor users who are running a supported Docker version (by @kdmccormick).