Deprecating Autotools as a way to build NetworkManager

[Ján Václav]

With this email, I would like to announce the plan to drop autotools
as a way to build NetworkManager from source.

- Current state
NetworkManager currently supports both Autotools and meson. Autotools
always existed as the primary way to build it, while meson was
introduced in 2017 with the intention that it would eventually replace
autotools. Currently both build systems have mostly the same
functionality and can be used interchangeably.

- Why?
The motivation behind this is that meson is a much more modern build
system which is also faster and more descriptive. On the other hand,
Autotools is complicated and hard to use in comparison. Dropping
Autotools also means that we can reduce duplication in terms of
building NM and unify the way all contributors build it.

- Plan
The current plan is to continue to support Autotools for the next
major release (1.48 - final release in about a month) but require the
user to pass an argument when using it, to acknowledge that it will be
dropped soon, and drop it when beginning the next development cycle
(1.49+).

- What you need to do
If you are currently using Autotools to build NetworkManager and want
some guidance on how to configure it to build NetworkManager, see the
CONTRIBUTING.md file within the repository:
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/main/CONTRIBUTING.md

--
Jan