autopilot_tester: fix speed factor to fix CI #22552

Job	Run time
build (check_format)	1m 8s
build (tests)	5m 57s
build (tests_coverage)	7m 16s
build (px4_fmu-v2_default stack_check)	3m 12s
build (validate_module_configs)	1m 9s
build (shellcheck_all)	1m 45s
build (NO_NINJA_BUILD=1 px4_fmu-v5_default)	4m 25s
build (NO_NINJA_BUILD=1 px4_sitl_default)	3m 11s
build (airframe_metadata)	1m 7s
build (module_documentation)	1m 19s
build (parameters_metadata)	1m 13s
	31m 42s

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