fuzz: posix: widen fuzz framing length to 2 bytes #23749

Job	Run time
LP64-WIP	3m 30s
build-windows (mnfst, imx8 imx8x)	9m 9s
manifest-check	2m 55s
build-windows (mnfst, tgl)	7m 31s
build-windows (mnfst, mtl)	9m 11s
build-windows (mnfst, ptl)	10m 25s
build-linux (mnfst, wcl imx95)	6m 2s
build-windows (mnfst, imx8m imx8ulp)	9m 31s
build-windows (mnfst, lnl)	8m 6s
build-windows (-d, mnfst, lnl)	8m 20s
build-linux (mnfst, lnl)	4m 16s
build-linux (mnfst, mtl)	3m 46s
build-linux (mnfst, ptl)	5m 26s
build-linux (mnfst, imx8m imx8ulp)	4m 21s
build-linux (mnfst, tgl)	3m 57s
build-linux (-d, mnfst, lnl)	4m 3s
build-linux (mnfst, imx8 imx8x)	4m 16s
build-linux (mnfst, tgl-h)	3m 51s
build-windows (mnfst, tgl-h)	8m 40s
compare-linux-win	28s
	1h 57m 44s

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