[Keyboard] Refactor JJ50 keyboard mapping to current standard (#9415)

keyboards/jj50/jj50.h

@@ -17,13 +17,9 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef KEYMAP_COMMON_H
-#define KEYMAP_COMMON_H
+#pragma once
 
 #include "quantum.h"
-#include "quantum_keycodes.h"
-#include "keycode.h"
-#include "action.h"
 
 #define LAYOUT_ortho_5x12( \
     K011, K010, K009, K008, K004, K005, K006, K007, K003, K002, K201, K000, \
@@ -40,5 +36,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 }
 
 #define LAYOUT LAYOUT_ortho_5x12
-
-#endif