Downgrade CI: raise SciMLBase compat floor to 2.146 (#92)

* Downgrade: raise SciMLBase compat floor to 2.146

The downgrade CI (which pins SciMLBase to its compat floor) was failing
with an unsatisfiable resolution. With SciMLBase pinned to the previous
floor (2.49), the test environment's solver stack (OrdinaryDiffEq /
OrdinaryDiffEqSDIRK / ModelingToolkit / MethodOfLines, pulled in via
test/Project.toml) could only resolve to versions on the old FastBroadcast
0.3 line, while RecursiveArrayTools (dragged in at 3.54 by the SciMLBase
dependency graph) requires FastBroadcast 1.3 — leaving no FastBroadcast
version installable.

The SciML stack switches from FastBroadcast 0.3 to 1.3 at
OrdinaryDiffEqCore 3.26, which requires SciMLBase >= 2.146. Raising the
floor to 2.146 lets the downgrade resolution land on a single, internally
consistent FastBroadcast-1.3 stack (verified locally on Julia 1.10:
SciMLBase 2.146.0, OrdinaryDiffEq 6.111.0, OrdinaryDiffEqSDIRK 1.14.0,
RecursiveArrayTools 3.54.0, FastBroadcast 1.3.2). The package source only
uses long-stable SciMLBase API (ODEProblem/ODEFunction/CallbackSet/
DiscreteCallback), so the raised floor is purely a downgrade-CI
accommodation and does not restrict any real functionality; the 3.x line
remains supported via the existing "3.1" range entry.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Re-trigger CI: clear self-hosted runner lost-communication flakes

The Core (julia 1 / pre) and QA (julia 1) test jobs failed with a null
conclusion on the Run tests step (and all subsequent steps) on
self-hosted runners — the lost-communication infrastructure flake, not a
test failure (julia-buildpkg, i.e. resolution + precompilation, succeeded
in every case). Verified locally that Core passes on Julia 1.12 and QA
passes on Julia 1.11/1.12, so this empty commit re-runs CI to land the
flaked jobs on healthy runners.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: ChrisRackauckas-Claude <accounts@chrisrackauckas.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

Project.toml

@@ -13,7 +13,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 CommonSolve = "0.2"
 ExplicitImports = "1"
 PrecompileTools = "1"
-SciMLBase = "2.49, 3.1"
+SciMLBase = "2.146, 3.1"
 Test = "1"
 julia = "1.10"