add pool for expanded posting slice (#8035) #15790

Job	Run time
Go build with -tags=stringlabels	2m 8s
Check misspelled words	10s
Go build for different platforms	5m 14s
Thanos end-to-end tests (8, 0)	5m 51s
Linters (Static Analysis) for Go	3m 53s
Thanos end-to-end tests (8, 1)	4m 57s
Thanos unit tests	12m 40s
Thanos end-to-end tests (8, 2)	4m 39s
Thanos end-to-end tests (8, 3)	5m 1s
Thanos end-to-end tests (8, 4)	8m 45s
Thanos end-to-end tests (8, 5)	5m 11s
Thanos end-to-end tests (8, 6)	5m 4s
Thanos end-to-end tests (8, 7)	4m 47s
	1h 8m 20s

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