Restore current SBML test-suite compatibility - #223

Rebased onto current main after #224 merged and revalidated at 18eb314e9c15114f029c78f6f6355882ea7aedda.

Local verification on Julia 1.12.6:

• GROUP=QA julia +1.12 --startup-file=no --project=. -e 'using Pkg; Pkg.test()': QA/qa.jl | 28/28; Testing SBMLToolkit tests passed; exit 0.\n- GROUP=Core julia +1.12 --startup-file=no --project=. -e 'using Pkg; Pkg.test()': events 3/3, reactions 28/28, rules 11/11, simresults 9/9, systems 44/44, utils 11/11, wuschel 2/2; Testing SBMLToolkit tests passed; exit 0.\n- julia +1.12 --project=.runic_env -m Runic --check .: exit 0 (the local Runic environment lives at the workspace root).\n- git diff --check origin/main...HEAD: exit 0.\n\nBefore the history update I fetched both upstream and the fork branch. The remote feature tip was still the previously audited 70b2e35252bd82fb7361667d930e2d28de7e3aad, with no remote-only additions; the push used an explicit force-with-lease for that SHA.

Exact downstream validation against the failing ModelingToolkit workflow is now complete.

Environment:

• Julia 1.12.6
• ModelingToolkit d39174937 (the exact clean master base of Fix collect_vars! after late invalidation on Julia 1.10 ModelingToolkit.jl#4852)
• SBMLToolkit PR head 18eb314e9c15114f029c78f6f6355882ea7aedda
• General registry commit cf87b2e4a16d9b7ba710aaac144d607d0bf724df / tree 31befd7172041c2f95b752ca5d7147232c79da23
• isolated depot, GROUP=All

I ran the same downstream workflow shape from the ModelingToolkit root:

using Pkg
Pkg.Registry.add()
Pkg.develop(PackageSpec(path = "./lib/ModelingToolkitBase"))
Pkg.develop(PackageSpec(path = "."))
Pkg.update()
Pkg.test(; coverage = true)

The unmodified SBMLToolkit main at 7dbc7bca71211d97ba2997b2c38a9f6d69c21827 reproduces the hosted failure locally (exit 1): its exact SBMLToolkitTestSuite = "0.0.5" constraint cannot resolve with the current SciMLBase/OrdinaryDiffEq/Sundials stack.

With this PR stacked, resolution selected SBMLToolkitTestSuite 1.1.2, OrdinaryDiffEq 7.2.0, Sundials 6.4.2, and SciMLBase 3.39.1. The exact workflow then exited 0 with Testing SBMLToolkit tests passed:

• Core/events.jl: 3/3
• Core/reactions.jl: 28/28
• Core/rules.jl: 11/11
• Core/simresults.jl: 9/9
• Core/systems.jl: 44/44
• Core/utils.jl: 11/11
• Core/wuschel.jl: 2/2
• total: 108/108

A first-parent compatibility bisect identifies 753fbc269868178401b9227a850203971412b220 (#199) as the first commit advertising the OrdinaryDiffEq 7 / ModelingToolkit 11 ecosystem while still constraining the test suite to the legacy 0.x line. That makes the ModelingToolkit failure pre-existing and independent of its PR. This PR repairs that dependency/test-stack boundary and supplies the source compatibility changes needed for the current stack.

Additional checks on this exact head: Runic --check exited 0, the branch is clean, and it is 0 commits behind current origin/main.