[async] Separate stdexec to a separate recipe

[vsytch]

I'm trying to use https://github.com/maikel/senders-io to incorporporate io-uring support, but it requires a patched version of stdexec. The local copy of stdexec in sdbusplus has a different directory layout than the upstream version, which makes it impossible to cherry-pick a patch.

Is there a plan to remove the local copy of stdexec and move to a bitbake recipe instead?

[williamspatrick]

I'd be ok to do that if someone wants to write a bitbake recipe and contribute code here and/or stdexec so that it can be picked up as a meson subproject. Right now stdexec is using conan + cmake, which is a pain to integrate into meson.

I'm expecting that most of stdexec will become part of std in C++26. There are also some header files that we are using out of stdexec that they haven't matured enough to be a proposal in C++26 yet, but are really useful. I don't think they currently even 'install' these because they haven't considered the API stable yet.