Fix the issues reported by phpcs

Above error/warnings are fixed.

Reviewed the patch #2. It looking fine.
Moving to RTBC.

Rashmisoni → made their first commit to this issue’s fork.

+   * @param \Drupal\Core\Routing\RouteMatchInterface $routeMatch
+   *   The RouteMatch service.

The service description can be better.

+   * Add noindex Headers.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\ResponseEvent $event
+   *   The Response Event.
+   */

Headers and Event are not at the beginning of the sentence.

+    // Get Configuration & Event Response.
+    $config = $this->configFactory->get('login_switch.settings');
+    $response = $event->getResponse();

That comment does not explain anything the code does not make already clear. Since those lines are edited, the comment can be removed.

-   * @var \Drupal\Core\ProxyClass\Routing\RouteBuilder.
+   * The routerBuilder.

Repeating the class name, even with a different spelling, is not adding a documentation comment for a class property.

+        '#title' => $this->t('Disable default user/@key route', ['@key' => $key]),

The article is missing.

+/**
+ * The ExceptionEventSubscriber Class.
+ */
+class ExceptionEventSubscriber implements EventSubscriberInterface {

Repeating the class name is not documenting a class. When class is not at the beginning of a sentence, it is not written in capital case.

+  /**
+   * The onException function.
+   */

That simply repeats the method name (and calls it function).

Fixed 1,3,4 feedback.

Neither one or the other of those patches fix what reported.