Vendor Update: go-gitlab v0.22.1 -> v0.31.0 (#11136)

* vendor update: go-gitlab to v0.31.0

* migrate client init to v0.31.0

* refactor

vendor/github.com/hashicorp/go-retryablehttp/roundtripper.go

@@ -0,0 +1,43 @@
+package retryablehttp
+
+import (
+	"net/http"
+	"sync"
+)
+
+// RoundTripper implements the http.RoundTripper interface, using a retrying
+// HTTP client to execute requests.
+//
+// It is important to note that retryablehttp doesn't always act exactly as a
+// RoundTripper should. This is highly dependent on the retryable client's
+// configuration.
+type RoundTripper struct {
+	// The client to use during requests. If nil, the default retryablehttp
+	// client and settings will be used.
+	Client *Client
+
+	// once ensures that the logic to initialize the default client runs at
+	// most once, in a single thread.
+	once sync.Once
+}
+
+// init initializes the underlying retryable client.
+func (rt *RoundTripper) init() {
+	if rt.Client == nil {
+		rt.Client = NewClient()
+	}
+}
+
+// RoundTrip satisfies the http.RoundTripper interface.
+func (rt *RoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt.once.Do(rt.init)
+
+	// Convert the request to be retryable.
+	retryableReq, err := FromRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// Execute the request.
+	return rt.Client.Do(retryableReq)
+}