Adding ability to specify the GitHub Server URL and allowing for it to differ from the Actions workflow host

__test__/git-auth-helper.test.ts

@@ -778,7 +778,8 @@ async function setup(testName: string): Promise<void> {
     sshKnownHosts: '',
     sshStrict: true,
     workflowOrganizationId: 123456,
-    setSafeDirectory: true
+    setSafeDirectory: true,
+    githubServerUrl: undefined
   }
 }