[DNM] west.yml: switch to private Zephyr repo #318

Job	Run time
LP64-WIP	4m 8s
manifest-check	2m 44s
build-linux (mnfst, tgl)	4m 33s
build-linux (mnfst, lnl)	4m 39s
build-linux (-d, mnfst, lnl)	4m 36s
build-linux (mnfst, ptl)	5m 42s
build-linux (mnfst, tgl-h)	4m 18s
build-windows (mnfst, lnl)	8m 50s
build-windows (-d, mnfst, lnl)	9m 28s
build-linux (mnfst, imx8m imx8ulp)	4m 31s
build-windows (mnfst, tgl-h)	9m 56s
build-linux (mnfst, mtl)	4m 25s
build-linux (mnfst, imx8 imx8x)	4m 54s
build-windows (mnfst, ptl)	10m 48s
build-windows (mnfst, mtl)	8m 47s
build-linux (mnfst, wcl imx95)	6m 52s
build-windows (mnfst, tgl)	8m 6s
build-windows (mnfst, imx8 imx8x)	11m 43s
build-windows (mnfst, imx8m imx8ulp)	10m 8s
compare-linux-win	29s
	2h 9m 37s

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