Retroactively cap DelayDiffEq at OrdinaryDiffEqCore 4.8.0

[ChrisRackauckas-Claude]

Summary

• cap DelayDiffEq 6.0.0 through 6.1.0 at OrdinaryDiffEqCore 4.8.0
• leave DelayDiffEq 6.1.1 and later unaffected

Why

Those DelayDiffEq releases call the pre-limiter DEOptions constructor. OrdinaryDiffEqCore 4.8.1 introduced the incompatible limiter-aware layout, so the current registry can resolve a combination that fails with a MethodError.

Since this was opened, DelayDiffEq 6.1.1 (Core floor 4.8.1) and 6.1.2 / 6.2.0 (Core floor 4.12.0) were registered, so the affected range is exactly 6 - 6.1.0 and the cap slots into the ["6 - 6.1.0"] table that master already has. The previously stacked OrdinaryDiffEqDefault change (#162780) landed via #162878 and is no longer part of this PR.

Verification

Pkg.Registry.compat_info over D/DelayDiffEq on master vs. this branch:

BEFORE (master)                      AFTER (this branch)
6.0.0 – 6.1.0  Core = 4              6.0.0 – 6.1.0  Core = 4 - 4.8.0
6.1.1          Core = 4.8.1 - 4      6.1.1          Core = 4.8.1 - 4
6.1.2, 6.2.0   Core = 4.12.0 - 4     6.1.2, 6.2.0   Core = 4.12.0 - 4

The original run reproduced the DEOptions MethodError with unmodified registry metadata and solved the representative delayed problem with the cap applied (see the earlier discussion above).

Please ignore this draft until it has been reviewed by @ChrisRackauckas.

🤖 Generated with Claude Code (model: claude-fable-5)
https://claude.ai/code/session_01YP75PszwM7qriCJho8QNQC

[ChrisRackauckas-Claude]

Cross-link from the clean Julia 1.10 ModelingToolkit initialization audit: after fixing the two independent collect_vars! invalidation errors in SciML/ModelingToolkit.jl#4852, the official GROUP=Initialization run has exactly 9 remaining errors, all DelayDiffEq.MethodOfSteps failures from the incompatible OrdinaryDiffEqCore.DEOptions constructor resolved by this cap. No collector errors remain in that run.

[ChrisRackauckas]

This is an extremely time sensitive simple retrocap but the people I am pinging are not responding today so I am going to merge as we really need to make sure we don't leave people hanging on this thing.

[github-actions]

This pull request has been inactive for 30 days and will be automatically closed 7 days from now. If this pull request should not be closed, please either (1) fix the AutoMerge issues and re-trigger Registrator, which will automatically update the pull request, or (2) post a comment explaining why you would like this pull request to be manually merged. It would also be helpful if you could post a message in the #pkg-registration channel of the JuliaLang Slack (https://julialang.org/slack/), to increase visibility. [noblock]

[ChrisRackauckas-Claude]

Rebased onto current master (42af7e6). The branch now carries a single one-line change: OrdinaryDiffEqCore = "4" → "4 - 4.8.0" in the existing ["6 - 6.1.0"] table of D/DelayDiffEq/Compat.toml. The stacked OrdinaryDiffEqDefault commit was dropped since #162878 already landed it. DelayDiffEq 6.1.1+ (registered after this PR opened) already floor Core at 4.8.1 / 4.12.0, so they are untouched — verified with Pkg.Registry.compat_info before/after in the PR body.

Please keep this open for manual merge: it is a retroactive cap, so Registrator cannot regenerate it.

🤖 Rebased by Claude Code (model: claude-fable-5) — https://claude.ai/code/session_01YP75PszwM7qriCJho8QNQC