ci(downgrade): allow-reresolve true (was false)

Strict no-reresolve can't reconcile floored core deps against the
latest-floating transitive SciML stack; reresolve still enforces the
floor [compat] pins but resolves a consistent set. Verified locally.

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

Author: ChrisRackauckas

.github/workflows/Downgrade.yml

@@ -22,5 +22,5 @@ jobs:
       julia-version: "1.10"
       group: "${{ matrix.group }}"
       skip: "Pkg,TOML"
-      allow-reresolve: false
+      allow-reresolve: true
     secrets: "inherit"