Stop restarting waybar entirely on updates

This had problems and like this we also won't have an ugly flash

migrations/1757512135.sh

@@ -0,0 +1,5 @@
+echo "Make it possible to remove update-available icon with signal in Waybar"
+
+if ! grep -q '"signal": 7' ~/.config/waybar/config.jsonc; then
+  sed -i '/"tooltip-format": "Omarchy update available",/a\    "signal": 7,' ~/.config/waybar/config.jsonc
+fi