release-25.2: roachtest: skip revision history and zone config in mixed-version backup on pre-24.1 tenants

[dt]

Backport 1 of 2 commits from #170069 on behalf of @dt.

(The second commit on the original PR is a CollectionConfig refactor of
infrastructure that does not exist on this branch, so it is omitted.)

Closes #170244.

---

Zone configuration is not supported in virtual clusters on versions
older than 24.1. When the mixed-version backup test runs with a
multitenant deployment starting from a pre-24.1 version, the
"configure gc policies" step fails with "operation is disabled within
a virtual cluster".

Rather than just skipping the GC TTL configuration, also skip
revision_history backups for these pre-24.1 multitenant runs. The GC
TTL only exists to bound MVCC history accumulation for revision history
backups, so if we're not using revision history, we don't need the TTL
either. AOST restore selection already checks withRevisionHistory() so
it correctly avoids picking an AOST when revision history is not
present.

---

Release justification: test-only roachtest fix for mixed-version backup pre-24.1 tenants

[blathers-crl]

Thanks for opening a backport.

Before merging, please confirm that it falls into one of the following categories (select one):

• Non-production code changes OR fixes for serious issues. Non-production includes test-only changes, build system changes, etc. Serious issues are defined in the policy as correctness, stability, or security issues, data corruption/loss, significant performance regressions, breaking working and widely used functionality, or an inability to detect and debug production issues.
• Other approved changes. These changes must be gated behind a disabled-by-default feature flag unless there is a strong justification not to. Reference the approved ENGREQ ticket in the PR body (e.g., "Fixes ENGREQ-123").

Add a brief release justification to the PR description explaining your selection.

Also, confirm that the change does not break backward compatibility and complies with all aspects of the backport policy.

All backports must be reviewed by the TL and EM for the owning area.

[trunk-io]

Merging to release-25.2 in this repository is managed by Trunk.

• To merge this pull request, check the box to the left or comment /trunk merge below.

After your PR is submitted to the merge queue, this comment will be automatically updated with its status. If the PR fails, failure details will also be posted here

[cockroach-teamcity]

This change is