cmd/mdatagen: introduce additional metadata for deprecated metrics #36561

Job	Run time
setup-environment	11s
lint	3m 9s
govulncheck	3m 14s
test-coverage	7m 30s
checks	1m 41s
cross-build-collector (darwin, arm64)	50s
cross-build-collector (linux, ppc64le)	54s
cross-build-collector (linux, 386)	55s
cross-build-collector (linux, s390x)	52s
cross-build-collector (windows, arm64)	1m 3s
cross-build-collector (darwin, amd64)	52s
unittest-matrix (ubuntu-latest, oldstable)	1m 26s
cross-build-collector (linux, riscv64)	1m 3s
cross-build-collector (linux, arm, 7)	51s
cross-build-collector (windows, amd64)	1m 3s
cross-build-collector (windows, 386)	55s
cross-build-collector (linux, arm64)	1m 4s
cross-build-collector (aix, ppc64)	59s
unittest-matrix (ubuntu-latest, stable)	1m 26s
cross-build-collector (linux, amd64)	55s
unittest	2s
	30m 55s

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