reduce brightness loop interval, update brightness value via loop

src/display.py

@@ -74,9 +74,7 @@ class DisplayBrightnessManager():
         return self.brightness_value
 
     def set_brightness_value(self, number: float):
-        res = subprocess.run(['light', '-S', f'{ number }%'])
-        if res.returncode != 0:
-            logger.warn(f'failed to set brightness: exit code { res.returncode }')
+        self.brightness_value_new = number
 
     def set_mode(self, mode: BrightnessMode):
         self.brightness_mode_new = mode
@@ -163,7 +161,7 @@ class DisplayBrightnessManager():
                     await self.dim_screen(50)
                     self.brightness_level = BrightnessLevel.LEVEL_BRIGHT
 
-            await asyncio.sleep(0.1)
+            await asyncio.sleep(0.05)
 
     async def run(self):
         tasks = [self.brightness_loop()]