Get rid of artifacts

[facchinm]

TODO:

• integrate https://github.com/arduino/sync_zephyr_artifacts in extras
• compile sync_zephyr_artifacts for the various OS and provide instructions on how to use it
• run bfg: java -jar bfg.jar --delete-folders "{firmwares,llext-edk}" --delete-files="{includes.txt,provides.ld,cflags.txt,cxxflags.txt}"
• force push the cleaned repo

[pillo79]

Changes in upstream repo branch:

• renamed post-build-tool to zephyr-sketch-tool
• merged sync-zephyr-artifact
• use copy with overwrite to avoid removing the whole variants folder
• detect file changes using git command (may be an issue on Windows, but the alternative is FUBAR 😢)
• added a package_tool.sh that builds a tool for release in distrib/ (all targets+JSON)

[KurtE]

What it help for us to play along with this Pull Request or better to wait until the dust settles?

[facchinm]

@KurtE better to wait a òlittle bit, there's no functional change here but only a cleanup 🙂