defmt related improvements

[bugadani]

In this PR:

• I've replaced my macros with the solution pasted from embassy. This means less use statements.
• I've updated CI to not activate both log and defmt at the same time
• Enabling log or defmt now enables the same feature for esp-hal
• I've matrixified CI to deduplicate the lists of examples
• ... probably something else I forgot

blocked on the next esp-hal release I've followed the beaten path of version-and-git-repo dependencies

[bugadani]

@bjoernQ @MabezDev after tons of back-and-forth, this should be ready for your attention.

[bjoernQ]

LGTM

[MabezDev]

Sorry @bugadani, can you switch back to the now-released crates.io versions for the hals? 😅

[bugadani]

@MabezDev I can remove the ref =-s if it makes a difference (though I'm quite sure they would be readded at some point anyway) but the versions are already the new ones.

Yup, I did it, otherwise users can't mix release versions of esp-hal with git versions of esp-wifi. Oops, good call, thanks!

[MabezDev]

Thank you @bugadani ! Once CI finishes I'll merge this!

[bugadani]

@MabezDev if I may bug you, the CI did finish ;)