nixos/power-management: fix deadlock with post-resume.{target,service}

Fixes a deadlock where post-resume.target has After=post-resume.service
and post-resume.service runs systemctl try-restart post-resume.target
the systemctl call cannot complete if post-resume.target was already
queued at that time.

nixos/modules/config/power-management.nix

···
         after = [ "suspend.target" "hibernate.target" "hybrid-sleep.target" "suspend-then-hibernate.target" ];
         script =
           ''
-            /run/current-system/systemd/bin/systemctl try-restart post-resume.target
+            /run/current-system/systemd/bin/systemctl try-restart --no-block post-resume.target
             ${cfg.resumeCommands}
             ${cfg.powerUpCommands}
           '';