Use the API URL from the environment if it is present.

src/feature-flags.test.ts

@@ -23,6 +23,7 @@ test.beforeEach(() => {
 const testApiDetails: GitHubApiDetails = {
   auth: "1234",
   url: "https://github.com",
+  apiURL: undefined,
 };
 
 const testRepositoryNwo = parseRepositoryNwo("github/example");