sway: switch to brightnessctl

`light` upstream repo is archived, so we have to switch to a maintained
alternative.

sway-config-fedora.spec.rpkg

@@ -41,9 +41,9 @@ Recommends: rofi-wayland
 Recommends: xdg-user-dirs
 Requires: /usr/bin/pgrep
 Requires: /usr/bin/pkill
+Requires: brightnessctl >= 0.5.1-11
 Requires: desktop-backgrounds-compat
 Requires: grimshot
-Requires: light
 Requires: lxqt-policykit
 Requires: playerctl
 Requires: pulseaudio-utils

sway/config.d/60-bindings-brightness.conf

@@ -1,18 +1,18 @@
-# Key bindings for brightness control using `light`.
+# Key bindings for brightness control using `brightnessctl`.
 # Displays a notification with the current value if /usr/bin/notify-send is available
 #
 # Brightness increase/decrease step can be customized by setting the `$brightness_step`
 # variable to a numeric value before including the file.
 #
-# Requires:     light
+# Requires:     brightnessctl >= 0.5.1-11
 # Recommends:   libnotify
 
 set $brightness_notification_cmd  command -v notify-send >/dev/null && \
-        VALUE=$(light) && VALUE=${VALUE%%.*} && \
+        VALUE=$(brightnessctl --percentage get) && \
         notify-send -e -h string:x-canonical-private-synchronous:brightness \
             -h "int:value:$VALUE" -t 800 "Brightness: ${VALUE}%"
 
 bindsym XF86MonBrightnessDown exec \
-        'STEP="$brightness_step" && light -U ${STEP:-5} && $brightness_notification_cmd'
+        'STEP="$brightness_step" && brightnessctl -q set ${STEP:-5}%- && $brightness_notification_cmd'
 bindsym XF86MonBrightnessUp exec \
-        'STEP="$brightness_step" && light -A ${STEP:-5} && $brightness_notification_cmd'
+        'STEP="$brightness_step" && brightnessctl -q set +${STEP:-5}% && $brightness_notification_cmd'