New API key for test optimization

Author: nccatoni

.github/workflows/system_tests.yml

@@ -29,7 +29,7 @@ jobs:
     uses: DataDog/system-tests/.github/workflows/system-tests.yml@main
     secrets:
       DD_API_KEY: ${{ secrets.DD_API_KEY }}
-      TEST_OPTIMIZATION_API_KEY: ${{ secrets.DD_API_KEY }}
+      TEST_OPTIMIZATION_API_KEY: ${{ secrets.TEST_OPTIMIZATION_API_KEY }}
     permissions:
       contents: read
       packages: write