scripts: west_commands: run: Add priority to run once config

[nordicjm]

Adds an optional priority parameter to the flash runner run once configuration which allows for deciding upon which file should ultimately be used

[nordicjm]

Have removed the check, it would no longer be possible to do it since one repo might have the full flash run once config and the repos that a user has might not have those qualifiers, have reduced it to just do a soc name check but this might also need to be removed in future

[57300]

Have removed the check, it would no longer be possible to do it since one repo might have the full flash run once config and the repos that a user has might not have those qualifiers, have reduced it to just do a soc name check but this might also need to be removed in future

Fine by me 👍 Sadly, that wasn't enough to get rid of the error, but I found another fix. There's a related bug which I decided to fix upstream first: zephyrproject-rtos#75601

[57300]

LGTM, please rebase