Feature request: Ability to list a file source for history archiving that will not also be added to import/export

[cat-bro]

We are interested in allowing users to archive their histories and free disk space.
I have added the following to file_sources.conf on the Galaxy Australia dev server

- type: s3fs
  label: Galaxy Australia Archive Storage
  endpoint_url: https://swift.rc.nectar.org.au:443
  id: usegalaxy-au-archive-test
  bucket: usegalaxy-au-archive-test
  doc: Galaxy Australia Archive Storage
  anon: false
  secret: {{ vault_nectar_melbournegvl_cb_ec2_secret_key }}
  key: {{ vault_nectar_melbournegvl_cb_ec2_access_key }}
  writable: true

The only purpose for this bucket is to hold archived histories - we have no wish to use it for import and export tools, however I can’t find an option to exclude this and it turns up as an option for both the uploader and the ‘Export to file’ tool.