fix: re-add s3cmd

Dockerfile

@@ -4,7 +4,8 @@ ADD src/fdroid.list /etc/apt/sources.list.d/fdroid.list
 ADD src/fdroid.asc /usr/share/keyrings/fdroid.asc
 RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get -y install --no-install-recommends python3-pip python3-wheel python3-setuptools apksigner fdroidserver && \
-    rm -rf /var/lib/apt/lists/*
+    rm -rf /var/lib/apt/lists/* && \
+    pip3 install s3cmd
 
 RUN unlink /usr/bin/apksigner
 ADD src/apksigner.sh /usr/bin/apksigner