rebase: bump golang.org/x/oauth2 in /actions/retest

Bumps [golang.org/x/oauth2](https://github.com/golang/oauth2) from 0.27.0 to 0.28.0.
- [Commits](https://github.com/golang/oauth2/compare/v0.27.0...v0.28.0)

---
updated-dependencies:
- dependency-name: golang.org/x/oauth2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

actions/retest/vendor/golang.org/x/oauth2/oauth2.go

@@ -288,7 +288,7 @@ func (tf *tokenRefresher) Token() (*Token, error) {
 	if tf.refreshToken != tk.RefreshToken {
 		tf.refreshToken = tk.RefreshToken
 	}
-	return tk, err
+	return tk, nil
 }
 
 // reuseTokenSource is a TokenSource that holds a single token in memory
@@ -356,11 +356,15 @@ func NewClient(ctx context.Context, src TokenSource) *http.Client {
 	if src == nil {
 		return internal.ContextClient(ctx)
 	}
+	cc := internal.ContextClient(ctx)
 	return &http.Client{
 		Transport: &Transport{
-			Base:   internal.ContextClient(ctx).Transport,
+			Base:   cc.Transport,
 			Source: ReuseTokenSource(nil, src),
 		},
+		CheckRedirect: cc.CheckRedirect,
+		Jar:           cc.Jar,
+		Timeout:       cc.Timeout,
 	}
 }