Remove the #[interrupt] macro

[MabezDev]

Following up from #1063 we need to:

• Remove the macro from esp-hal-macros
• Document how users can still install handlers by default by using #[no_mangle] or #[export_name = ""]
  • Maybe we don't want to document this?
• Document upgrade paths from #[interrupt] to #[handler]

[bjoernQ]

Document how users can still install handlers by default by using #[no_mangle] or #[export_name = ""]

Maybe we shouldn't document that. I will most probably just do that in esp-wifi but if users do that for an interrupt which gets taken over by an async driver they might have a bad time debugging that? Explaining all that (and maybe additionally explaining ::interrupt::bind_interrupt) is probably a bit overwhelming for most users and others can figure things out on themselves.

[jessebraham]

#1409 probably closes this? @bjoernQ proposed a migration guide which we can use for the next release, and I think, at least for now, maybe not talking about this potential #[no_mangle]/#[export_name] foot gun is probably for the best 😅

[jessebraham]

Gonna close this, feel free to re-open if needed.