image-builder: Add python3-debian

In order to be able to generate the BOM file of the image add python3-debian
package.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>

image-builder/Dockerfile

@@ -48,6 +48,7 @@ RUN apt-get update && \
         parted \
         procps \
         python3 \
+        python3-debian \
         qemu-utils \
         qemu-user-static \
         rsync \