The dev build SDKs are not in $FLATCAR_DEV_BUILDS/sdk but published under
$FLATCAR_DEV_BUILDS/developer/sdk.
Add an environment variable to specify where the SDK is to be found
but default to $FLATCAR_DEV_BUILDS/sdk if it is not specified.
From Jenkins this variable is exported as DOWNLOAD_ROOT_SDK.
More space can be saved by removing things that get overwritten on
the next job run, but they are used after this script runs (e.g.
for fingerprinting). Drop the cleanup from these scripts and move
it all to the post-build pipeline stage.
We are going to restore the split-script setup from the old Jenkins
server. This ensures that the each version's release process is
actually running with scripts in the correct release branch. It
also allows branching the VM format lists.
Note that the scripts added here only cover the currently active
jobs in the main build pipeline. There is no reason to add other
jobs, since they are mostly just running a single command using a
mantle binary from its master branch.
The scripts in this repository pick up after Jenkins has set up an
environment with all parameters and credentials defined, and an SDK
was prepared and validated.
