bump to protocol 9 (#221) #781

Job	Run time
Build (x86_64-pc-windows-msvc)	10m 21s
Build (aarch64-pc-windows-msvc)	11m 40s
Build (x86_64-apple-darwin)	5m 25s
Build (aarch64-apple-darwin)	9m 16s
Build (aarch64-apple-ios)	7m 22s
Build (aarch64-apple-ios-sim)	6m 3s
Build (x86_64-unknown-linux-gnu)	6m 14s
Build (aarch64-unknown-linux-gnu)	5m 1s
Build (aarch64-linux-android)	6m 27s
Build (armv7-linux-androideabi)	6m 25s
Build (x86_64-linux-android)	7m 21s
	1h 21m 35s

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