Flux: Ensure connections to InflxuDB are closed (#26735)

* Flux: Ensure connections to InflxuDB are closed

pkg/tsdb/influxdb/flux/flux.go

@@ -29,6 +29,7 @@ func Query(ctx context.Context, dsInfo *models.DataSource, tsdbQuery *tsdb.TsdbQ
 	if err != nil {
 		return nil, err
 	}
+	defer runner.client.Close()
 
 	for _, query := range tsdbQuery.Queries {
 		qm, err := GetQueryModelTSDB(query, tsdbQuery.TimeRange, dsInfo)