detect_test: Do not overwrite supplied threshold #17429

Job	Run time
LP64-WIP	4m 2s
build-windows (imx8 imx8x imx8m imx8ulp)	7m 18s
manifest-check	41s
build-windows (mtl)	5m 34s
build-linux (mnfst, imx8 imx8x imx8m imx8ulp)	5m 23s
build-windows (tgl tgl-h)	6m 33s
build-linux (mnfst, mtl)	4m 38s
build-windows (-d, mtl)	5m 41s
build-linux (mnfst, lnl)	4m 31s
build-linux (mnfst, tgl tgl-h)	5m 25s
build-linux (zmain, imx8 imx8x imx8m imx8ulp)	5m 11s
build-linux (zmain, mtl)	4m 25s
build-linux (zmain, lnl)	4m 34s
build-linux (zmain, tgl tgl-h)	5m 33s
build-linux (-d, mnfst, mtl)	4m 29s
compare-linux-win	19s
	1h 14m 17s

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