Remove package index files in all Dockerfiles consistently

buildd.df

@@ -8,4 +8,5 @@ FROM  ${DEVUAN_IMAGE}
 LABEL maintainer="Olaf Meeuwissen <paddy-hack@member.fsf.org>"
 
 RUN apt-get update -q \
-    && apt-get install build-essential -q -y
+    && apt-get install build-essential -q -y \
+    && remove-apt-lists

migrate.df

@@ -21,4 +21,4 @@ RUN url=http://auto.mirror.devuan.org/merged \
     && (rm /etc/apt/trusted.gpg~ || true) \
     && DEBIAN_FRONTEND=noninteractive apt-get dist-upgrade -q -y \
     && DEBIAN_FRONTEND=noninteractive apt-get --purge autoremove -q -y \
-    && rm /var/lib/apt/lists/*_*
+    && rm /var/lib/apt/lists/*_dists_*