Fix cancel auto merge bug (#36341)

routers/api/v1/repo/pull.go

@@ -1322,7 +1322,7 @@ func CancelScheduledAutoMerge(ctx *context.APIContext) {
 	}
 
 	if ctx.Doer.ID != autoMerge.DoerID {
-		allowed, err := access_model.IsUserRepoAdmin(ctx, ctx.Repo.Repository, ctx.Doer)
+		allowed, err := pull_service.IsUserAllowedToMerge(ctx, pull, ctx.Repo.Permission, ctx.Doer)
 		if err != nil {
 			ctx.APIErrorInternal(err)
 			return