update changelog for stable version 0.21.7 with deps update #340

Job	Run time
build (windows-latest, aarch64-pc-windows-msvc)	13m 16s
build (windows-latest, x86_64-pc-windows-msvc)	12m 23s
build (ubuntu-22.04-arm, aarch64-unknown-linux-gnu)	10m 34s
build (ubuntu-22.04, x86_64-unknown-linux-gnu)	8m 57s
	45m 10s

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