DOCKER_BUILDKIT=0 is depracated

[EveningStarlight]

Current State

Staged builds moved most images to the new docker build version.
Only remote-desktop still uses DOCKER_BUILDKIT=0

Issue

The classic build option DOCKER_BUILDKIT=0 is deprecated and will eventually lose support.

Moving to the new version, by removing this flag, was briefly tested.
Two images have issues with the new build, remote-desktop and sas,
who both have Out of Memory errors when trying to export the layers.

Possible options for solving the error:

• Set the parallelism to 1: no improvement
• Set memory limits: no improvement
• Disable caching: no improvement
• use --output=type=docker: no improvement
• Investigate: Increase the runner size #699
• Minimize the number of layers created by the Dockerfile

[EveningStarlight]

Splitting up dockerbits into separate layers does not help compile the layers.

mid-sas image builds

final sas image still has tame failure issue.

[EveningStarlight]

Staged builds moved most images to the new docker build version.
Only remote-desktop still uses DOCKER_BUILDKIT=0