Prepare release 1.6.0-M2 (#356) #891

Job	Run time
features (--no-default-features)	1m 38s
linting (stable)	49s
test (ubuntu-latest, stable)	1m 9s
features (--no-default-features --features serialization)	1m 38s
linting (beta)	54s
test (ubuntu-latest, beta)	1m 16s
features (--no-default-features --features serial)	1m 40s
test (windows-latest, stable)	3m 34s
features (--no-default-features --features tls)	1m 59s
test (windows-latest, beta)	2m 33s
bindings-linux (x86_64-unknown-linux-gnu)	2m 27s
bindings-linux (i686-unknown-linux-gnu)	2m 31s
bindings-macos (x86_64-apple-darwin)	2m 0s
bindings-linux (x86_64-unknown-linux-musl)	2m 39s
bindings-windows (x86_64-pc-windows-msvc, true)	8m 22s
documentation	4m 8s
bindings-linux (arm-unknown-linux-gnueabihf)	2m 32s
bindings-windows (i686-pc-windows-msvc, false)	5m 46s
bindings-linux (arm-unknown-linux-musleabihf)	2m 48s
conformance	10m 6s
bindings-linux (aarch64-unknown-linux-gnu)	2m 29s
guide	1m 13s
bindings-linux (aarch64-unknown-linux-musl)	2m 36s
bindings-linux (armv7-unknown-linux-gnueabihf)	2m 32s
bindings-linux (arm-unknown-linux-gnueabi)	2m 31s
packaging	3m 12s
release	7m 58s
	1h 23m 0s

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