remove unused variable causing double register in prometheus

Author: ayu-devtron

internal/middleware/instrument.go

@@ -32,11 +32,6 @@ var (
 	}, []string{"path", "method", "status"})
 )
 
-var PgQueryDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
-	Name: "pg_query_duration_seconds",
-	Help: "Duration of PG queries",
-}, []string{"label"})
-
 var CdDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
 	Name: "cd_duration_seconds",
 	Help: "Duration of CD process",