chore(ci): use dd-sts for system-tests test optimization

Author: nccatoni

.github/workflows/system_tests.yml

@@ -34,10 +34,12 @@ jobs:
       TEST_OPTIMIZATION_API_KEY: ${{ secrets.TEST_OPTIMIZATION_API_KEY }}
     permissions:
       contents: read
+      id-token: write
       packages: write
     with:
       library: python_lambda
       binaries_artifact: binaries
       scenarios_groups: tracer_release
       skip_empty_scenarios: true
       push_to_test_optimization: true
+      dd_sts_policy: datadog-lambda-python