feat: add Gitea workflow that builds package on tag push.

debian-package/build.sh

@@ -11,6 +11,7 @@ esac
 mkdir -p out
 
 $CONTAINER_RUNTIME build --build-arg HOST_UID=$(id -u) --build-arg HOST_GID=$(id -g) -t vpn-router-builder "$@" .
-$CONTAINER_RUNTIME run --rm -v "$(pwd)/out:/mnt" vpn-router-builder sh -c 'cp -p /out/* /mnt/'
+# Artifacts are streamed out as a tar archive, so no bind mount is needed.
+$CONTAINER_RUNTIME run --rm vpn-router-builder tar -cf - -C /out . | tar -xf - -C out
 
 echo "Build artifacts written to out/"