Drop allow-reresolve input from downgrade workflow(s)

The reusable SciML/.github downgrade workflows now always use
allow_reresolve: false and no longer accept an allow-reresolve input
(see SciML/.github#71). Remove the now-invalid input so this caller keeps
working once @v1 is retagged.

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

@@ -19,5 +19,4 @@ jobs:
       group: "Core"
       # SymbolicAnalysis skipped: 0.3.x doesn't support Symbolics 7 (required by ModelingToolkit 11)
       skip: "Pkg,TOML,LinearAlgebra,Logging,Printf,Random,SparseArrays,Test,SymbolicAnalysis"
-      allow-reresolve: false
     secrets: "inherit"

.github/workflows/DowngradeSublibraries.yml

@@ -21,4 +21,3 @@ jobs:
       julia-version: "1.10"
       # SymbolicAnalysis skipped: 0.3.x doesn't support Symbolics 7 (required by ModelingToolkit 11)
       skip: "Pkg,TOML,LinearAlgebra,Logging,Printf,Random,SparseArrays,Test,SymbolicAnalysis"
-      allow-reresolve: true