ci: add multi-artifact build #630

Job	Run time
Build and package cores	8m 24s
Split off zephyr_contrib	15s
Split off zephyr_main	18s
Split off zephyr	8s
Split off zephyr_unoq	18s
Test zephyr_main:nano33ble	2m 39s
Test zephyr_main:portentac33	2m 55s
Test zephyr_main:niclasense	2m 39s
Test zephyr:unoq	2m 41s
Test zephyr_main:giga	2m 50s
Test zephyr_main:opta	2m 48s
Test zephyr_contrib:ek_ra8d1	2m 45s
Test zephyr_main:portentah7	2m 46s
Test zephyr_contrib:frdm_mcxn947	2m 36s
Test zephyr_contrib:frdm_rw612	2m 41s
Publish jsons	16s
Collect logs	7s
Publish core	0s
verify-core	0s
cleanup-artifacts	6s
	37m 12s

Provide feedback