[Vendor] upgrade google/go-github to v32.1.0 (#12361) (#12390)

* upgrate go-github client to v32.1.0

* migrate

vendor/github.com/google/go-github/v32/github/timestamp.go

@@ -0,0 +1,41 @@
+// Copyright 2013 The go-github AUTHORS. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package github
+
+import (
+	"strconv"
+	"time"
+)
+
+// Timestamp represents a time that can be unmarshalled from a JSON string
+// formatted as either an RFC3339 or Unix timestamp. This is necessary for some
+// fields since the GitHub API is inconsistent in how it represents times. All
+// exported methods of time.Time can be called on Timestamp.
+type Timestamp struct {
+	time.Time
+}
+
+func (t Timestamp) String() string {
+	return t.Time.String()
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+// Time is expected in RFC3339 or Unix format.
+func (t *Timestamp) UnmarshalJSON(data []byte) (err error) {
+	str := string(data)
+	i, err := strconv.ParseInt(str, 10, 64)
+	if err == nil {
+		t.Time = time.Unix(i, 0)
+	} else {
+		t.Time, err = time.Parse(`"`+time.RFC3339+`"`, str)
+	}
+	return
+}
+
+// Equal reports whether t and u are equal based on time.Equal
+func (t Timestamp) Equal(u Timestamp) bool {
+	return t.Time.Equal(u.Time)
+}