fix(agent99): silence check progress stream

scripts/reboot-recovery/tests/test_agent99_remote_atomic_deploy_transport_contract.py

@@ -671,6 +671,7 @@ def test_check_mode_uses_bounded_control_command_without_ssh_stdin(
     assert "agent99-contract-check.ps1" in check_script
     assert "Get-FileHash" in check_script
     assert "runtimeContract" in check_script
+    assert check_script.count("ProgressPreference") == 2
     assert "remoteWritePerformed" in check_script
     assert "$z[$n]=$false" in check_script
     for write_command in (