Pass GITHUB_WORKSPACE explicitly to WSL install step

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: TGJLS

.github/workflows/test.yaml

@@ -162,6 +162,8 @@ jobs:
 
       - name: Install adaptix-testing
         shell: wsl-bash {0}
+        env:
+          GITHUB_WORKSPACE: ${{ github.workspace }}
         run: |
           cp -r "$(wslpath "$GITHUB_WORKSPACE")" /tmp/testing-kit
           cd /tmp/testing-kit