refactor: Add more checks to pre-commit

Updated existing pre-commit hooks and added some new hooks:

- Remove trailing whitespace
- Ensure every non-empty file ends with a new line
- Check YAML file validity
- Prevent adding large files
- Ensure any scripts with shebangs are executable

Added a GitHub action to run pre-commit on every commit. Removed any
existing actions which duplicate pre-commit.

Ran pre-commit on the codebase.

app/src/activity.c

@@ -74,8 +74,8 @@ void activity_work_handler(struct k_work *work) {
     } else
 #endif /* IS_ENABLED(CONFIG_ZMK_SLEEP) */
         if (inactive_time > MAX_IDLE_MS) {
-        set_state(ZMK_ACTIVITY_IDLE);
-    }
+            set_state(ZMK_ACTIVITY_IDLE);
+        }
 }
 
 K_WORK_DEFINE(activity_work, activity_work_handler);

app/src/display/widgets/Kconfig

@@ -33,7 +33,7 @@ config ZMK_WIDGET_PERIPHERAL_STATUS
     depends on BT && ZMK_SPLIT_BLE && !ZMK_SPLIT_ROLE_CENTRAL
     default y if BT && ZMK_SPLIT_BLE && !ZMK_SPLIT_ROLE_CENTRAL
     select LV_USE_LABEL
-    
+
 config ZMK_WIDGET_WPM_STATUS
     bool "Widget for displaying typed words per minute"
     depends on !ZMK_SPLIT || ZMK_SPLIT_ROLE_CENTRAL