Branching for NetBSD 10

[Martin Husemann <martin%duskware.de@localhost>]

After a bit more than two years after the first NetBSD 9 release
(9.0 happened February 14, 2020) and nearly a year after the last
(so far) netbsd-9 release (9.2 happened May 12, 2021) we are in
the final steps to prepare for the next really great release:

We are planning to branch netbsd-10 in about a week from now.

It seems that -current is in good shape overall, and we hope to get
the big blockers resolved before the release. There is a list
here:

	http://wiki.netbsd.org/releng/netbsd-10/

The most user visible fallout preventing testing of the new beta
versions is likely the DRM/KMS update and the current massive fallout
on intel i915 chips, here is an excerpt of the open PRs:

	https://gnats.NetBSD.org/56608
	https://gnats.NetBSD.org/56648
	https://gnats.NetBSD.org/56672
	https://gnats.NetBSD.org/56724
	https://gnats.NetBSD.org/56727
	https://gnats.NetBSD.org/56740
	https://gnats.NetBSD.org/56761
	https://gnats.NetBSD.org/56765

We hope to get this issues resolved soonish, but couldn't allow them to
further delay this long overdue branch.

We don't yet know how long the branch will take to the first release
(NetBSD 10), but hope it will not be more than three months. [But note
that all my personal estimates on NetBSD-10 have been off by years, so
this might need a correction - we will see once i915 works again.]

Martin