Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

search/searcher/optimize_no_knn.go

@@ -0,0 +1,31 @@
+//  Copyright (c) 2023 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !vectors
+// +build !vectors
+
+package searcher
+
+import (
+	"context"
+
+	"github.com/blevesearch/bleve/v2/search"
+	index "github.com/blevesearch/bleve_index_api"
+)
+
+func optimizeKNN(ctx context.Context, indexReader index.IndexReader,
+	qsearchers []search.Searcher) error {
+	// No-op
+	return nil
+}