pmb.helpers.run_core: fix sudo timer when not using sudo

pmb.config.sudo expects a list of commands + args, so when a string is
passed (e.g. "true"), it results in pmb trying to execute the equivalent
of "$ t r u e":

(8/119) Installing linux-purism-librem5 (6.3.4-r0)

doas: t: command not found
doas: t: command not found
doas: t: command not found
doas: t: command not found

Reviewed-by: Oliver Smith <ollieparanoid@postmarketos.org>
Link: https://lists.sr.ht/~postmarketos/pmbootstrap-devel/%3C20230613141929.15718-1-clayton@craftyguy.net%3E

pmb/helpers/run_core.py

@@ -230,7 +230,7 @@ def sudo_timer_iterate():
     if pmb.config.which_sudo() == "sudo":
         subprocess.Popen(["sudo", "-v"]).wait()
     else:
-        subprocess.Popen(pmb.config.sudo("true")).wait()
+        subprocess.Popen(pmb.config.sudo(["true"])).wait()
 
     timer = threading.Timer(interval=60, function=sudo_timer_iterate)
     timer.daemon = True