Increase Librem 5 image size

See merge request !175

byzantium: Use non-https URLs for the moment

See merge request !174

Space is tight during installations and even more so with byzatium
so free enough room.

The https ones hit I/O errors on the server side.

Support byzantium

See merge request !173

This is only needed until we have everything in. Building
byzantium now will help us to see problems compared to
Bullseye.

This uses landing and CI to get off the ground but
we can reduce step by step.

Set flash-kernel's machint type based on board revision

See merge request !172

This will allow to build differnt images until uboot catches up.

Revert "Make amber-phone images possible right now"

See merge request !170

This reverts commit 1c342b2a.

We can use plain amber again.

Make amber-phone images possible right now

See merge request !169

amber-phone-staging has about everything now but amber-phone
is still waiting for transitions. So in order to be able to
have images with a correct source.list bootstrap with
amber-phone-staging and switch back to amber-phone afterwards.

This can be removed in about a week when packages transitioned,
we can also drop 0037c22d then.

pureos: Temporarily add amber-proposed-upates

See merge request !168

We only need this until librem5-devkit-base >= 0.0.3 migrated but without
that we don't get a bootable kernel.

root.sh: Add plymouth's default theme configuration

See merge request !165

Increase image sizes by 300M to compensate for bigger /boot partition

See merge request !167

conf/board: Increase the boot partition size to 512M

See merge request !166

Currently used 200M is too small to hold the kernels
before autoremoval logic has a chance to kick in.

Allow to build against Debian Bullseye too

See merge request !164

On PureOS Amber that is less of a concern since it's stable now (and we
could use pinning) and on bullseye we don't care yet

Update ci repo key

See merge request Librem5/image-builder!163

I thought we'd get them but it's stored in the repo. This
will move into a deb package too.

Temporarily drop gnome-dev from x86 images

See merge request Librem5/image-builder!162

It can't install due to

Librem5/librem5-base!136

so let's drop that until the package migrated.

board: Adjust to branch rename

See merge request Librem5/image-builder!161

The linux-next branch lost it's 'linux-' to avoid confusion
with upstream's linux-next tree.

Don't inherit MIRROR from environment

See merge request Librem5/image-builder!158

Increase max size of image

See merge request Librem5/image-builder!160

x86_64 qemu images are failing to build in Jenkins.

https://arm01.puri.sm/job/Images/job/Image%20Build/3568/console

    update-initramfs: Generating /boot/initrd.img-4.19.0-5-amd64
    cp: error writing '/var/tmp/mkinitramfs_urPgne//lib/udev/ata_id': No space left on device
    E: /usr/share/initramfs-tools/hooks/udev failed with return 1.
    update-initramfs: failed for /boot/initrd.img-4.19.0-5-amd64 with 1.
    dpkg: error processing package initramfs-tools (--configure):
     installed initramfs-tools package post-installation script subprocess returned error exit status 1

This commit increases the size of the virtual disk used to build the
image.

Don't inherit $MIRROR from the environment. $mirror gets overridden later
from sourced configuration in conf/dists/*

Don't try to run extlinux

See merge request Librem5/image-builder!157

This does not exist on arm64 and it's not needed.

Explicitly install vmdebootstrap/qemu-user-static on Laniakea Spark instance

See merge request Librem5/image-builder!156

build-image: Exit in case of an unknown dist

See merge request Librem5/image-builder!155

When using the spark builder setup don't carry on if the dist
is unknown.