v4 does not support buildkit

[KasonBraley]

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Ory Network Project

No response

Describe the bug

#416 added support for BuildKit when building images for v3. In v4 that support is missing on the BuildOptions type. v3's BuildOptions had a Version field to enable.

Was this intentional?

Reproducing the bug

v3's BuildOptions has the Version field to enable buildkit.

https://pkg.go.dev/github.com/ory/dockertest/v3#BuildOptions

type BuildOptions struct {
	Dockerfile string
	ContextDir string
	BuildArgs  []dc.BuildArg
	Platform   string
	// Version specifies the builder to use. "1" for classic, "2" for BuildKit
	Version string
	Auth    dc.AuthConfigurations
}

The Version field is missing from BuildOptions on v4.
https://pkg.go.dev/github.com/ory/dockertest/v4#BuildOptions

type BuildOptions struct {
	// Dockerfile is the name of the Dockerfile within the ContextDir.
	// Defaults to "Dockerfile" if empty.
	Dockerfile string

	// ContextDir is the directory containing the Dockerfile and build context.
	// This directory will be archived and sent to the Docker daemon.
	// REQUIRED - build will fail if empty.
	ContextDir string

	// Tags are the tags to apply to the built image.
	// If empty, the image name from BuildAndRun will be used.
	Tags []string

	// BuildArgs are build-time variables passed to the Dockerfile.
	// Use pointers to distinguish between empty string and unset.
	// Example: map[string]*string{"VERSION": &versionStr}
	BuildArgs map[string]*string

	// Labels are metadata to apply to the built image.
	// Example: map[string]string{"version": "1.0", "env": "test"}
	Labels map[string]string

	// NoCache disables build cache when set to true.
	// Useful for ensuring a clean build.
	NoCache bool

	// ForceRemove always removes intermediate containers, even on build failure.
	// Useful for keeping the build environment clean.
	ForceRemove bool
}

Relevant log output

Relevant configuration

Version

v4

On which operating system are you observing this issue?

None

In which environment are you deploying?

None

Additional Context

No response