Setting up script and documentation to configure buildkit

[fahedouch]

Hi Folks,

The current implementation of dib uses Kaniko as the build backend. This ticket aims to migrate the builder implementation to use BuildKit, which provides better performance, caching, and functionality.

The target of this ticket is to set up script(s) and configuration to install and run BuildKit:

We have two options to set up BuildKit:

• Setting up BuildKit with containerd worker: BuildKit relies on containerd to manage containers and images, etc. containerd needs to be up and running on the host (supports rootless and rootful).
• Setting up BuildKit with OCI worker: BuildKit manages containers and images, etc. containerd isn't needed. This worker relies on runc for container execution. (I think this is what we need in the first implementation stage as it requires fewer dependencies.)

Note: The OCI worker cannot access base images (FROM images in Dockerfiles) managed by containerd.

The second part of this ticket covers the documentation of setting up BuildKit for dib.