TestBuildDependsOn, Subset, DependentImage, SubDependencies,
LongOutputLine, DependentImageWithProfile, Escaped, Tags and Secrets
become scenarios: models inline (the long-line Dockerfile generated
with strings.Repeat instead of 34 copy-pasted lines), image names
project-scoped with Defer cleanup, and the secrets build asserts
ImageExists on top of the Dockerfile's own diff checks.
Kept legacy: TestLocalComposeBuild (DOCKER_BUILDKIT=0/1 matrix over a
shared fixture with fixed names and host port), the buildx-builder
family (SSH, platforms, privileged, entitlements, builder, TLS) which
provisions builders and dind daemons, and TestBuildImageDependencies
(classic/bake matrix). Their fixtures under build-test/ stay; the
single-purpose subdirectories are removed.
Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>
