There has to be step between 3.x and 4.x version because of other
reasons than updater's incompatibility. That gives us possibility to
define new lowest supported version of updater-ng for 4.x releases.
Thanks to that we can remove some obsolete crap.

It is planned to bump minimal version of updater even higher as soon as
relevant updater's release is out.

This reverts commit 68aa24aa.

luajit: reflect latest upstream changes (see https://git.openwrt.org/?p=feed/packages.git;a=commit;h=ba5e9aa9458c6d12ec8acc3798ea95c3c0cc897a )

If we need them then we should port them and return them to lists.

Will it survive?

Dependencies that made sense were moved to updater. uci was dropped
because it should not most likely be required (python3-uci or liblua-uci
are in dependencies). libgcc should be transitional dependency and I
should not probably be as updater-ng dependency.

This reverts commit ca16a82d.

I disagree!

Original idea was that user can replace these components with some other
implementation but there is no possible other implementation in OpenWRT.
Default tools used by OpenWRT are disabled in Turris OS build and thanks
to that we just don't have any alternative except of using syslog and
cron from Turris OS.

Updater is just dummy package that is only needed for migration
purposes.

This command deploys extension of OpenWRT build that can be used to
always build tip of the git branch. It is intended for software
development.