clean up dockerfile for docker versions

base-dockercli/Dockerfile

@@ -1,11 +1,5 @@
-# syntax = docker/dockerfile:1
+# syntax = docker/dockerfile:latest
 
 FROM modem7/borgmatic-docker:latest
-COPY entry.sh /entry.sh
-RUN apk update \
-    && apk add --no-cache \
-    docker-cli \
-    && rm -rf /var/cache/apk/* \
-              /.cache \
-              && chmod 755 /entry.sh
+COPY --chmod=755 entry.sh /entry.sh
 CMD ["/entry.sh"]

base-liveinstall/Dockerfile

@@ -1,9 +1,6 @@
-# syntax = docker/dockerfile:1
+# syntax = docker/dockerfile:latest
 
 FROM modem7/borgmatic-docker:latest
-COPY entry.sh /entry.sh
-COPY wtfc.sh /wtfc.sh
-RUN rm -rf /var/cache/apk/* \
-           /.cache \
-           && chmod 755 /entry.sh /wtfc.sh
+COPY --chmod=755 entry.sh /entry.sh
+COPY --chmod=755 wtfc.sh /wtfc.sh
 CMD ["/entry.sh"]