rebase: bump google.golang.org/grpc from 1.59.0 to 1.60.1

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.59.0 to 1.60.1.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.59.0...v1.60.1)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/appengine/urlfetch/urlfetch.go

@@ -7,6 +7,7 @@
 package urlfetch // import "google.golang.org/appengine/urlfetch"
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -18,7 +19,6 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
-	"golang.org/x/net/context"
 
 	"google.golang.org/appengine/internal"
 	pb "google.golang.org/appengine/internal/urlfetch"
@@ -44,11 +44,10 @@ type Transport struct {
 var _ http.RoundTripper = (*Transport)(nil)
 
 // Client returns an *http.Client using a default urlfetch Transport. This
-// client will have the default deadline of 5 seconds, and will check the
-// validity of SSL certificates.
+// client will check the validity of SSL certificates.
 //
-// Any deadline of the provided context will be used for requests through this client;
-// if the client does not have a deadline then a 5 second default is used.
+// Any deadline of the provided context will be used for requests through this client.
+// If the client does not have a deadline, then an App Engine default of 60 second is used.
 func Client(ctx context.Context) *http.Client {
 	return &http.Client{
 		Transport: &Transport{