Fix starboard toolchain when multiple are used #16164

Job	Run time
linux-cobalt / initialize	1m 19s
linux-x64 / initialize	1m 17s
linux-x64 / docker-build-image	3m 40s
linux-cobalt / docker-build-image	3m 33s
linux-cobalt / x64_devel	24m 58s
linux-cobalt / x64_debug	24m 7s
linux-cobalt / x64_qa	25m 8s
linux-cobalt / x64_gold	26m 11s
linux-x64 / x64_devel	20m 30s
linux-x64 / x64_debug	21m 19s
linux-x64 / x64_qa	20m 14s
linux-x64 / x64_gold	21m 14s
	3h 13m 30s

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