Deprecate collectd/mysql monitor #11274

Job	Run time
setup-environment	1m 52s
generate-metrics	4m 28s
gofmt	4m 22s
tidy	1m 9s
coverage	7m 58s
cross-compile (binaries-darwin_amd64)	4m 49s
cross-compile (binaries-darwin_arm64)	4m 30s
lint	13m 17s
cross-compile (binaries-linux_amd64)	4m 28s
cross-compile (binaries-linux_arm64)	4m 25s
cross-compile (binaries-windows_amd64)	4m 22s
test	13m 43s
cross-compile (binaries-linux_ppc64le)	4m 43s
	1h 14m 6s

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