provide vendor dir for nix

vendor/github.com/sagikazarmark/slog-shim/json_handler_120.go

@@ -0,0 +1,24 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.21
+
+package slog
+
+import (
+	"io"
+
+	"golang.org/x/exp/slog"
+)
+
+// JSONHandler is a Handler that writes Records to an io.Writer as
+// line-delimited JSON objects.
+type JSONHandler = slog.JSONHandler
+
+// NewJSONHandler creates a JSONHandler that writes to w,
+// using the given options.
+// If opts is nil, the default options are used.
+func NewJSONHandler(w io.Writer, opts *HandlerOptions) *JSONHandler {
+	return slog.NewJSONHandler(w, opts)
+}