Add support for v4 CI related API

internal/upstream/routes.go

@@ -130,12 +130,14 @@ func (u *Upstream) configureRoutes() {
 		route("PUT", gitProjectPattern+`gitlab-lfs/objects/([0-9a-f]{64})/([0-9]+)\z`, lfs.PutStore(api, proxy), isContentType("application/octet-stream")),
 
 		// CI Artifacts
+		route("POST", apiPattern+`v4/jobs/[0-9]+/artifacts\z`, contentEncodingHandler(artifacts.UploadArtifacts(api, proxy))),
 		route("POST", ciAPIPattern+`v1/builds/[0-9]+/artifacts\z`, contentEncodingHandler(artifacts.UploadArtifacts(api, proxy))),
 
 		// Terminal websocket
 		wsRoute(projectPattern+`environments/[0-9]+/terminal.ws\z`, terminal.Handler(api)),
 
-		// Long poll and limit capacity given to builds/register.json
+		// Long poll and limit capacity given to jobs/request and builds/register.json
+		route("", apiPattern+`v4/jobs/request\z`, ciAPILongPolling),
 		route("", ciAPIPattern+`v1/builds/register.json\z`, ciAPILongPolling),
 
 		// Explicitly proxy API requests