Fix downgrade CI: run downgrade leg on Julia 1.11; revert misdiagnosed FunctionWrappers floor

The Downgrade (Core) job was Unsatisfiable on lts (Julia 1.10). Root cause:
the resolver (julia-downgrade-compat -> Resolver.jl) minimizes Julia to the
floor of its --julia range, and on lts that range (1.10) admits 1.10.0. But
every Mooncake 0.5.x test extra requires julia >= 1.10.8, so Mooncake can never
be placed -> Unsatisfiable. Even at julia 1.10.8 the Enzyme 0.13 + EnzymeCore
0.8 + Mooncake 0.5 minimum-version set has no solution on the 1.10 LTS stdlib
line; it only resolves once Julia advances to 1.11.6 (Mooncake 0.5's 1.11
floor), where the newer stdlib set admits the whole floor set.

Fix: pin the Downgrade caller to julia-version "1.11" (the resolver picks
1.11.6 and resolves cleanly). The core package's 1.10 support remains exercised
by the regular Tests workflow.

Also revert the earlier FunctionWrappers compat floor raise (1 -> 1.1.3) and the
1.9.1 -> 1.9.2 version bump: that change was based on a misreading (no test dep
in the registry constrains FunctionWrappers, and the source only uses the
FunctionWrapper{R,A} constructor available since 1.0.0). It did not fix the
downgrade failure. Project.toml now matches main.

Verified locally on Julia 1.11: the actual julia-downgrade-compat downgrade.jl
resolves the merged test project and exits 0 ("Successfully resolved minimal
versions"). On Julia 1.10 it still reports Unsatisfiable, confirming the
diagnosis.

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

@@ -28,5 +28,13 @@ jobs:
     uses: "SciML/.github/.github/workflows/downgrade.yml@v1"
     with:
       group: "${{ matrix.group }}"
-      julia-version: "lts"
+      # The Mooncake/Enzyme test extras only resolve at their declared minimum
+      # versions on Julia >= 1.11.6: every Mooncake 0.5.x requires julia >= 1.10.8,
+      # and the Enzyme 0.13 + EnzymeCore 0.8 + Mooncake 0.5 floor set has no
+      # minimum-version solution on the 1.10 LTS stdlib line. The downgrade
+      # resolver minimizes julia to the floor of its --julia range, so on lts
+      # (=1.10, which admits 1.10.0) it strands Mooncake -> Unsatisfiable. Pin the
+      # downgrade leg to 1.11 (resolves to julia 1.11.6); the core package's 1.10
+      # support is still exercised by the regular Tests workflow.
+      julia-version: "1.11"
     secrets: "inherit"

Project.toml

@@ -1,7 +1,7 @@
 name = "FunctionWrappersWrappers"
 uuid = "77dc65aa-8811-40c2-897b-53d922fa7daf"
 authors = ["Chris Elrod <elrodc@gmail.com> and contributors"]
-version = "1.9.2"
+version = "1.9.1"
 
 [deps]
 FunctionWrappers = "069b7b12-0de2-55c6-9aab-29f3d0a68a2e"
@@ -20,7 +20,7 @@ FunctionWrappersWrappersMooncakeExt = "Mooncake"
 [compat]
 Enzyme = "0.13"
 EnzymeCore = "0.8"
-FunctionWrappers = "1.1.3"
+FunctionWrappers = "1"
 Mooncake = "0.5"
 PrecompileTools = "1"
 SafeTestsets = "0.1, 1"