Build breaks if reserved layer added but Studio disabled #3045
Description
If your keymap contains a layer with status = "reserved" but CONFIG_ZMK_STUDIO=n, then it will fail to compile with a 5000 line long error. The error starts with
zmk/app/src/keymap.c:60:81: warning: excess elements in array initializer
Some other context
zmk/app/src/keymap.c:60:81: note: (near initialization for 'zmk_keymap_layer_names')
60 | #define LAYER_NAME(node) DT_PROP_OR(node, display_name, DT_PROP_OR(node, label, ""))
| ^~
The culprit seems to be this code at line 98 of keymap.c:
static const char *zmk_keymap_layer_names[ZMK_KEYMAP_LAYERS_LEN] = {
DT_INST_FOREACH_CHILD_SEP(0, LAYER_NAME, (, ))};
Where ZMK_KEYMAP_LAYERS_LEN uses DT_FOREACH_CHILD_STATUS_OKAY when Studio is disabled, the code here (and in several other places in keymap.c) does not, so it tries to add more items to the array than there are layers.