Mark the moonlander keyboard default music map as weak (#18715)

This allows user keymaps to set a different music map.

keyboards/moonlander/moonlander.c

@@ -358,6 +358,7 @@ void keyboard_post_init_kb(void) {
 
 #if defined(AUDIO_ENABLE) && defined(MUSIC_MAP)
 // clang-format off
+__attribute__ ((weak))
 const uint8_t music_map[MATRIX_ROWS][MATRIX_COLS] = LAYOUT_moonlander(
     58, 59, 60, 61, 62, 63, 64,    65, 66, 67, 68, 69, 70, 71,
     44, 45, 46, 47, 48, 49, 50,    51, 52, 53, 54, 55, 56, 57,

keyboards/moonlander/moonlander.h

@@ -55,9 +55,9 @@ extern bool mcp23018_leds[];
     { k60, k61, k62, k63, k64, k65, k66 }, \
     { k70, k71, k72, k73, k74, k75, k76 }, \
     { k80, k81, k82, k83, k84, k85, k86 }, \
-    { KC_NO,k91, k92, k93, k94, k95, k96 }, \
+    { KC_NO, k91, k92, k93, k94, k95, k96 }, \
     { KC_NO, KC_NO, ka2, ka3, ka4, ka5, ka6 }, \
-    { KC_NO, KC_NO, KC_NO, kb3, kb4, kb5, kb6  } \
+    { KC_NO, KC_NO, KC_NO, kb3, kb4, kb5, kb6 } \
 }
 // clang-format on
 
@@ -83,4 +83,4 @@ typedef union {
 
 extern keyboard_config_t keyboard_config;
 
-bool is_transport_connected(void);
+bool is_transport_connected(void);