base: Install less pager

Refs. sysadm-environment#5560

apps/swh-base/Dockerfile

@@ -10,7 +10,8 @@ ARG configdir=/etc/${user}
 RUN apt-get update && \
     apt-get upgrade -y && \
     apt-get install -y git sed \
-      gzip lzip zstd cpio && \
+      gzip lzip zstd cpio \
+      less && \
     apt-get clean && \
     addgroup --gid ${userid} ${user} && \
     useradd --gid ${groupid} --uid ${userid} -m -d ${workdir} ${user} && \