chore(ci): remove dd_sts_policy from system-tests subworkflow

Author: nccatoni

.github/workflows/run-system-tests.yaml

@@ -77,7 +77,6 @@ jobs:
       excluded_scenarios: APM_TRACING_E2E_OTEL,APM_TRACING_E2E_SINGLE_SPAN,PROFILING  # exclude flaky scenarios
       skip_empty_scenarios: true
       push_to_test_optimization: true
-      dd_sts_policy: dd-trace-java-system-tests
 
   # Ensure the main job is run to completion
   check: