Merge pull request cockroachdb#105209 from cockroachdb/blathers/backp…

…ort-release-23.1-105156

release-23.1: roachtest: fix tpchvec in some cases

pkg/cmd/roachtest/tests/tpchvec.go

@@ -259,7 +259,7 @@ func (p *tpchVecPerfTest) postTestRunHook(
 
 			// Check whether we can reproduce this slowness to prevent false
 			// positives.
-			var helper tpchVecPerfHelper
+			helper := newTpchVecPerfHelper(runConfig.setupNames)
 			for setupIdx, setup := range runConfig.clusterSetups {
 				performClusterSetup(t, conn, setup)
 				result, err := c.RunWithDetailsSingleNode(