Downgrade CI: raise root ADTypes lower bound to 1.22.0

[ChrisRackauckas-Claude]

Note: This PR should be ignored until reviewed by @ChrisRackauckas.

Fixes the Downgrade / Downgrade Tests - InterfaceI failure that has been red on master (runs 2026-06-09T10:30 and 14:40) and on every PR branch since.

Root cause

The job fails at the resolve step, before any tests run:

Unsatisfiable requirements detected for package ADTypes:
 ├─ restricted to versions 1.16.0-1 by OrdinaryDiffEq
 ├─ restricted to versions 1.22.0-1 by OrdinaryDiffEqExtrapolation (fixed at 2.2.0)
 └─ restricted to versions 1.16.0 by an explicit requirement — no versions left

#3701 (commit 8a82eab) raised the ADTypes lower bound in the sublibraries (e.g. lib/OrdinaryDiffEqExtrapolation → 1.22.0) but left the root Project.toml at 1.16.0. The downgrade workflow pins patch-specific root compat entries to their lower bound, so the root pins ADTypes = 1.16.0 while the path-fixed sublibraries require >= 1.22.0 — unsatisfiable.

I audited all other root-vs-sublib compat lower bounds: ADTypes is the only conflicting patch-specific root entry (1.22.0 is the max sublib bound). Major-only entries like SciMLBase = "3" are left loose by the downgrade tooling, so the sublibs' SciMLBase >= 3.1/3.10 bounds resolve fine (to v3.10.0 minimal).

Verification

Ran the downgrade scenario locally on master + this one-line change (Julia 1.11, minimal-version manifest, Pkg.test with allow_reresolve=false, GROUP=InterfaceI):

• Resolution succeeds, picking ADTypes v1.22.0 and SciMLBase v3.10.0 (the minimal versions satisfying all sublib constraints).
• The full InterfaceI suite passed: Testing OrdinaryDiffEq tests passed, exit code 0, zero failures.

🤖 Generated with Claude Code

[ChrisRackauckas-Claude]

Adding the trigger timeline (why this surfaced June 7 rather than at #3701 on May 30):

#3701 relied on allow_reresolve: true in the runtest step, which let the test sandbox re-resolve ADTypes up to 1.22 despite the root lower-bound pin. SciML/.github#71 changed the reusable downgrade workflow to always use allow_reresolve: false; #3728 (46d11cd, 2026-06-07T12:12Z) adopted it here. Master Downgrade run history flips exactly there:

• dab0d74 2026-06-07T10:30Z — success (last green master Downgrade run)
• 46d11cd (Drop now-invalid allow-reresolve input from downgrade workflow(s) #3728) 2026-06-07T12:12Z — failure, and every master run since fails with this ADTypes unsatisfiability.

Also noting for completeness: DowngradeSublibraries on master fails for a different reason (per-sublibrary minimal test-dep conflicts, e.g. lib/OrdinaryDiffEqCore: pinned DifferentiationInterface 0.7.16 vs NLSolversBase via NLsolve/DiffEqDevTools). Not addressed by this PR; needs a separate bound-raising pass across lib/* Projects.

[ChrisRackauckas-Claude]

CI confirms the fix: the Downgrade / Downgrade Tests - InterfaceI check now passes on this PR (it fails on master and every other branch). Ready for review — merging this unblocks the Downgrade check repo-wide. DowngradeSublibraries remains red from the separate pre-existing cause tracked in #3736.