remove the "registry_tag_deprecated" images

In the base container images, we have (debian) images that are dumped directly at the root of the container registry, so that we have containers.torproject.org/tpo/tpa/base-images:stable that's actually containers.torproject.org/tpo/tpa/base-images/debian:stable

This is marked as deprecated in the source code, but the images are still there, and the tags still being pushed.

affected repositories, snowflake:

• am3o/snowflake
• Gedsh/snowflake
• itchyonion/snowflake
• just1602/snowflake
• micah/snowflake
• mingyech/snowflake
• obble/snowflake
• theodorsm/snowflake
• tpo/anti-censorship/pluggable-transports/snowflake (see tpo/anti-censorship/pluggable-transports/snowflake!401 (merged))
• WofWca/snowflake

others:

• kez/dangerzone-builder retired
• micah/base-images clone of this repository
• tpo/tpa/ci-test

this is a requirement before the image build cleanup in !29 (merged).