Use spaces, not tabs

.devcontainer/Dockerfile

@@ -1,7 +1,7 @@
 from zmkfirmware/zephyr-west-action-arm
 
 RUN apt-get -y update && \
-	apt-get -y upgrade && \
+    apt-get -y upgrade && \
     apt-get install --no-install-recommends -y \
     ssh \
     gpg && \