Change keyboard level include guards to pragma once (#14248)

* Change keyboard level include guards to `pragma once`

And clean up a lot of layout macros

* Oops

* Remove dangling endif

keyboards/meira/lighting.h

@@ -1,9 +1,6 @@
-#ifndef LIGHTING_H
-#define LIGHTING_H
+#pragma once
 
 void led_test(void);
 void force_issi_refresh(void);
 void set_backlight(uint8_t level);
 void set_backlight_by_keymap(uint8_t col, uint8_t row);
-
-#endif