Add Dockerfile optimizations

@ThePrimeagen did these on-stream.

Dockerfile

@@ -4,6 +4,15 @@ RUN mkdir -p /app/firmware
 
 WORKDIR /app
 
+COPY config/west.yml config/west.yml
+
+# West Init
+RUN west init -l config
+# West Update
+RUN west update
+# West Zephyr export
+RUN west zephyr-export
+
 COPY config config
 COPY bin/build.sh ./
 

bin/build.sh

@@ -5,12 +5,6 @@ set -e
 PWD=$(pwd)
 TIMESTAMP=$(date -u +"%Y%m%d%H%M%S")
 
-# West Init
-west init -l config
-# West Update
-west update
-# West Zephyr export
-west zephyr-export
 # West Build (left)
 west build -s zmk/app -d build/left -b adv360_left -- -DZMK_CONFIG="${PWD}/config"
 # Adv360 Left DTS File