simplfy code

Author: sivchari

cmd/clusterctl/client/repository/repository_github.go

@@ -505,12 +505,9 @@ func (g *gitHubRepository) handleGithubErr(err error, message string, args ...in
 		return errors.New("rate limit for github api has been reached. Please wait one hour or get a personal API token and assign it to the GITHUB_TOKEN environment variable")
 	}
 
-	var errorResponse *github.ErrorResponse
-	if errors.As(err, &errorResponse) {
-		ghErr := err.(*github.ErrorResponse)
-		if ghErr.Response.StatusCode == http.StatusNotFound {
-			return errNotFound
-		}
+	var ghErr *github.ErrorResponse
+	if errors.As(err, &ghErr) && ghErr.Response.StatusCode == http.StatusNotFound {
+		return errNotFound
 	}
 	return errors.Wrapf(err, message, args...)
 }