We don't actually need the development headers, instead using this as
a hack to be agnostic to the version scheme and pull in the latest.
related:
https://github.com/spesmilo/electrum/pull/8185https://github.com/spesmilo/electrum/pull/8320https://github.com/spesmilo/electrum/issues/8328#issuecomment-1518061250
debian 11 (stable) only has libsecp256k1-0
debian 12 (testing) atm only has libsecp256k1-1
ubuntu 23.04 only has libsecp256k1-1
I expect libsecp256k1-2 might soon get packaged too, now that upstream secp released v0.3.0.
So what do we tell users to install? well, turns out most distros have libsecp256k1-dev, which
just pulls in the latest secp.
Caveat: if there is a new secp release that actually gets packaged on a distro before we can react,
then this new instruction will not work.
note: unclear where to put these files... `contrib/build-wine/` and `contrib/osx/`
contain binary-building-related files. maybe we could have a `doc/` folder
if the need for more similar files arise.
atm there are these two, plus maybe `contrib/docker_notes.md`.