test-and-lint

Update module github.com/caddyserver/certmagic to v0.21.4 #397

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Run time

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Job	Run time
golangci-lint (linux)	1m 28s
gotest (ubuntu)	32s
codespell	10s
golangci-lint (windows)	1m 25s
gotest (macos)	36s
gotest (windows)	29s
	4m 40s