Move ForwardDiff CUDA error handling outside @testset

The @testset for-loop wraps each iteration body in its own try-catch,
intercepting the CUDA error before the inner try-catch can handle it.
Move the try-catch into a helper function called before the testset
body, so the CUDA alignment error is caught cleanly.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ChrisRackauckas

test/gpu_kernel_de/forward_diff.jl

@@ -35,28 +35,42 @@ monteprob = EnsembleProblem(prob, prob_func = prob_func, safetycopy = false)
 # NOTE: On some CUDA GPUs (e.g. V100), SVector{3, ForwardDiff.Dual{Nothing, Float32, 6}}
 # triggers a misaligned address error (CUDA error code 716) due to the 84-byte element size
 # not satisfying GPU memory alignment requirements. This is a CUDA.jl issue, not DiffEqGPU.
-@testset "ForwardDiff with $alg" for alg in (
+# Test that the solve either succeeds or fails with the known alignment error.
+function try_solve(monteprob, alg, backend; kwargs...)
+    try
+        sol = solve(monteprob, alg, EnsembleGPUKernel(backend, 0.0); kwargs...)
+        return sol
+    catch e
+        if occursin("misaligned address", string(e))
+            return nothing  # Known CUDA alignment issue
+        else
+            rethrow(e)
+        end
+    end
+end
+
+for alg in (
         GPUTsit5(), GPUVern7(), GPUVern9(), GPURosenbrock23(autodiff = false),
         GPURodas4(autodiff = false), GPURodas5P(autodiff = false),
         GPUKvaerno3(autodiff = false), GPUKvaerno5(autodiff = false),
     )
     @info alg
-    try
-        sol = solve(
-            monteprob, alg, EnsembleGPUKernel(backend, 0.0),
-            trajectories = 2, save_everystep = false, adaptive = false, dt = 0.01f0
-        )
+    sol = try_solve(
+        monteprob, alg, backend,
+        trajectories = 2, save_everystep = false, adaptive = false, dt = 0.01f0
+    )
+    if sol !== nothing
         @test length(sol) == 2
-        asol = solve(
-            monteprob, alg, EnsembleGPUKernel(backend, 0.0),
-            trajectories = 2, adaptive = true, dt = 0.01f0
-        )
+    else
+        @test_broken false  # Known CUDA alignment issue with ForwardDiff Duals
+    end
+    asol = try_solve(
+        monteprob, alg, backend,
+        trajectories = 2, adaptive = true, dt = 0.01f0
+    )
+    if asol !== nothing
         @test length(asol) == 2
-    catch e
-        if occursin("misaligned address", string(e))
-            @test_broken false  # Known CUDA alignment issue with ForwardDiff Duals
-        else
-            rethrow(e)
-        end
+    else
+        @test_broken false  # Known CUDA alignment issue with ForwardDiff Duals
     end
 end