[mdatagen] bug fix - reaggreagate_set test generation #36686

Job	Run time
setup-environment	19s
govulncheck	3m 20s
checks	2m 22s
unittest-matrix (ubuntu-latest, stable)	5m 14s
unittest-matrix (ubuntu-latest, oldstable)	5m 14s
lint	5m 14s
test-coverage	5m 12s
cross-build-collector (aix, ppc64)	59s
cross-build-collector (darwin, amd64)	56s
cross-build-collector (linux, 386)	52s
cross-build-collector (linux, arm64)	56s
cross-build-collector (linux, amd64)	55s
cross-build-collector (linux, riscv64)	57s
cross-build-collector (linux, ppc64le)	54s
cross-build-collector (windows, arm64)	54s
cross-build-collector (windows, amd64)	59s
cross-build-collector (linux, s390x)	1m 0s
cross-build-collector (linux, arm, 7)	53s
cross-build-collector (windows, 386)	54s
cross-build-collector (darwin, arm64)	1m 0s
unittest	5s
	39m 9s

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