vm/starnix: update syntax for ffx target list #18619

Job	Run time
dashboard	2m 5s
old	6m 57s
build	3m 14s
arch (presubmit_arch_windows)	3m 44s
race	8m 53s
gvisor	4m 0s
race_dashboard	2m 47s
aux	4m 46s
arch (presubmit_arch_darwin)	3m 56s
arch (presubmit_arch_executor)	3m 21s
arch (presubmit_arch_openbsd)	3m 54s
arch (presubmit_arch_linux)	10m 46s
arch (presubmit_arch_netbsd)	4m 5s
arch (presubmit_arch_freebsd)	6m 20s
	1h 8m 48s

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