refactor: Remove unimportant labels

Removed "label" properties which no longer have any function.

Labels are still used as layer names and as identifiers for sending
behaviors between sides of a split keyboard, so those have been left
alone for now.

app/boards/shields/snap/snap_right.overlay

@@ -9,7 +9,6 @@
 / {
 kscan_direct: kscan_direct {
     compatible = "zmk,kscan-gpio-direct";
-    label = "DIRECT";
     input-gpios
         = <&pro_micro 10 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>
         ;