Remove scheduler: luci from new build_aar_module_test (flutter#154945)

This option was deprecated (/removed?) in the time since the test was originally disabled.

See flutter#109712, flutter#109714

Author: gmackall

.ci.yaml

@@ -439,7 +439,6 @@ targets:
       tags: >
         ["devicelab","hostonly"]
       task_name: build_aar_module_test
-    scheduler: luci
     runIf:
       - dev/**
       - packages/flutter_tools/**