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/osprette/osprette.overlay

@@ -26,7 +26,6 @@ RC(0,0) RC(1,0) RC(1,1) RC(1,2) RC(1,3) RC(1,4) RC(1,5) RC(1,6) RC(1,7) RC(1,8)
 
     kscan0: kscan_0 {
         compatible = "zmk,kscan-gpio-matrix";
-        label = "KSCAN";
         diode-direction = "row2col";
 
         col-gpios