Raise DataDrivenLux Distributions floor to 0.25.123 for downgrade CI

[ChrisRackauckas-Claude]

Ignore until reviewed by @ChrisRackauckas.

Problem

The only red lane on master is Downgrade Sublibraries / test (lib/DataDrivenLux). (Root CI, Sublibrary CI, and Downgrade are all green post-#624.) It fails at the Pkg.test sandbox resolution with:

ERROR: Unsatisfiable requirements detected for package ModelingToolkitBase [7771a370]:
 ├─restricted by compatibility requirements with ModelingToolkit to versions: 1.30.0-1.45.0
 └─restricted by compatibility requirements with SymbolicUtils to versions: 1.0.0-1.29.1 — no versions left

Root cause

• The root DataDrivenDiffEq compat floors ModelingToolkit = "11.21.0". The lowest MTK satisfying that (11.21.0) requires ModelingToolkitBase >= 1.30.0, which requires SymbolicUtils >= 4.23.1.
• At --min, the Distributions = "0.25" floor in lib/DataDrivenLux resolves to Distributions 0.25.88, whose transitive constraints cap SymbolicUtils <= 4.21.0.
• >= 4.23.1 vs <= 4.21.0 → UNSAT.

Note: this is distinct from #624, which carried the release-independent code/test fixes but deliberately left the downgrade floor decision unmade.

Fix

Raise the lib/DataDrivenLux floor to Distributions = "0.25.123". Bisected against the binding MTK 11.21.0 floor:

Distributions	resolves with MTK 11.21.0?
0.25.122	UNSAT
0.25.123	OK

0.25.123 is the lowest 0.25.x whose transitive graph admits SymbolicUtils >= 4.23.1. The compat upper bound is unchanged (0.25.123 means >=0.25.123,<0.26), so regular CI keeps selecting the latest 0.25.x and is unaffected.

Verification (local, Julia 1.10.11, clean depot)

• julia-downgrade-compat@v2 downgrade.jl (Resolver.jl --min, alldeps merged mode) against lib/DataDrivenLux: Successfully resolved minimal versions.
• The Pkg.test sandbox resolution that previously threw the UNSAT now succeeds; it resolves ModelingToolkitBase and SymbolicUtils at versions >= the floors that were impossible before.

🤖 Generated with Claude Code