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/arm/pillbug/pillbug.dts

@@ -26,7 +26,6 @@
         compatible = "gpio-leds";
         blue_led: led_0 {
             gpios = <&gpio0 20 GPIO_ACTIVE_LOW>;
-            label = "Blue LED";
         };
     };
 
@@ -39,7 +38,6 @@
 
     vbatt: vbatt {
         compatible = "zmk,battery-voltage-divider";
-        label = "BATTERY";
         io-channels = <&adc 2>;
         output-ohms = <2000000>;
         full-ohms = <(2000000 + 820000)>;
@@ -89,7 +87,6 @@
     status = "okay";
     cdc_acm_uart: cdc_acm_uart {
         compatible = "zephyr,cdc-acm-uart";
-        label = "CDC_ACM_0";
     };
 };
 
@@ -105,12 +102,10 @@
         #size-cells = <1>;
 
         sd_partition: partition@0 {
-            label = "mbr";
             reg = <0x00000000 0x00001000>;
         };
 
         code_partition: partition@1000 {
-            label = "code_partition";
             reg = <0x00001000 0x000d3000>;
         };
 
@@ -124,12 +119,10 @@
          * if enabled.
          */
         storage_partition: partition@d4000 {
-            label = "storage";
             reg = <0x000d4000 0x00020000>;
         };
 
         boot_partition: partition@f4000 {
-            label = "adafruit_boot";
             reg = <0x000f4000 0x0000c000>;
         };
     };