Add support for debian 12 (bookworm)

Background

Currently, our package source list (build/debian-repos/ironbank.list) for debian only points to bullseye's package sources.

Associated bootstrap ticket: https://repo1.dso.mil/platform-one/private/big-bang/ironbank/ironbank-bootstrap-values/-/issues/10

We need to update this to either:

• Use similar template vars like we're doing for the ubi conf (i.e. releasevar)
  • Not finding anything at first glance but maybe there are options I'm not seeing
• Provide all of the sources and let apt figure out which ones to use
  • Not sure if this will work or cause issues with pulling 11 resources for a deb 12 image
  • Need to test this
• Template our the ironbank.list with the appropriate source (bullseye vs. bookworm)
  • This will almost definitely mean that debian 11 and debian 12 will need different os-type tags to provide which source to use, which is fine but it would be preferred if they match between debian versions

Acceptance Criteria

• Debian 11+12 can pull deps from their package sources

Definition of Done

• Project pipeline runs successfully
• Solution is captured as code and/or documentation and merge requests have been submitted
• Code review completed and merge request approved/merged
• All Acceptance Criteria have been completed