fix(ci): avoid Windows CUDA 12.5 toolkit meta-package

Author: abetlen

.github/workflows/build-wheels-cuda.yaml

@@ -145,14 +145,36 @@ jobs:
           $cudaChannel = "nvidia/label/cuda-$cudaVersion"
           if ($IsLinux) {
             $nvccPackage = "${cudaChannel}::cuda-nvcc_linux-64"
+            $cudaPackages = @("${cudaChannel}::cuda-toolkit=$cudaVersion", $nvccPackage)
           } elseif ($IsWindows) {
             $nvccPackage = "${cudaChannel}::cuda-nvcc_win-64"
+            if ($cudaVersion -like '12.5.*') {
+              # The Windows 12.5 toolkit meta-package pulls conda compiler
+              # activation scripts that can overflow cmd.exe's line limit after
+              # MSVC is already initialized. The build only needs nvcc, cudart,
+              # and headers from the NVIDIA label.
+              $cudaPackages = @($nvccPackage)
+            } else {
+              $cudaPackages = @("${cudaChannel}::cuda-toolkit=$cudaVersion", $nvccPackage)
+            }
           } else {
             throw 'Unsupported CUDA wheel build platform'
           }
           # Keep nvcc, cudart, and headers on the same NVIDIA label so the
           # detected toolkit version matches the published wheel tag.
-          mamba install -y --channel-priority flexible --override-channels -c $cudaChannel "${cudaChannel}::cuda-toolkit=$cudaVersion" $nvccPackage "${cudaChannel}::cuda-cudart" "${cudaChannel}::cuda-cudart-dev"
+          $mambaArgs = @(
+            'install',
+            '-y',
+            '--channel-priority',
+            'flexible',
+            '--override-channels',
+            '-c',
+            $cudaChannel
+          ) + $cudaPackages + @(
+            "${cudaChannel}::cuda-cudart",
+            "${cudaChannel}::cuda-cudart-dev"
+          )
+          & mamba @mambaArgs
           if ($LASTEXITCODE -ne 0) {
             exit $LASTEXITCODE
           }