minor #12702 Remove ErrorRenderer reference everywhere (yceruto)

This PR was merged into the 4.4 branch.

Discussion
----------

Remove ErrorRenderer reference everywhere

Things have changed since then 🤷‍♂️

partially fixing #12621

Commits
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9457979 Remove ErrorRenderer reference everywhere

Author: javiereguiluz

components/error_handler.rst

@@ -67,11 +67,6 @@ to enable this error handler::
 
     ErrorHandler::register();
 
-.. tip::
-
-    If you want to get even better exception pages, install the
-    :doc:`ErrorRenderer component </components/error_renderer>` too.
-
 Catching PHP Function Errors and Turning Them into Exceptions
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -145,11 +140,6 @@ to enable this exception handler::
 
     ExceptionHandler::register();
 
-.. tip::
-
-    If you want to get even better exception pages, install the
-    :doc:`ErrorRenderer component </components/error_renderer>` too.
-
 .. _component-debug-class-loader:
 
 Class Loading Debugger

components/error_renderer.rst

@@ -566,7 +566,7 @@ below for more details).
     The listener has several goals:
 
     1) The thrown exception is converted into a
-       :class:`Symfony\\Component\\ErrorRenderer\\Exception\\FlattenException`
+       :class:`Symfony\\Component\\ErrorHandler\\Exception\\FlattenException`
        object, which contains all the information about the request, but which
        can be printed and serialized.
 

components/http_kernel.rst

@@ -247,7 +247,7 @@ the request that will be dispatched to your controller. In addition, your contro
 will be passed two parameters:
 
 ``exception``
-    A :class:`\\Symfony\\Component\\ErrorRenderer\\Exception\\FlattenException`
+    A :class:`\\Symfony\\Component\\ErrorHandler\\Exception\\FlattenException`
     instance created from the exception being handled.
 
 ``logger``

controller/error_pages.rst

@@ -69,7 +69,7 @@ Our code is now much more concise and surprisingly more robust and more
 powerful than ever. For instance, use the built-in ``ExceptionListener`` to
 make your error management configurable::
 
-    $errorHandler = function (Symfony\Component\ErrorRenderer\Exception\FlattenException $exception) {
+    $errorHandler = function (Symfony\Component\ErrorHandler\Exception\FlattenException $exception) {
         $msg = 'Something went wrong! ('.$exception->getMessage().')';
 
         return new Response($msg, $exception->getStatusCode());
@@ -91,7 +91,7 @@ The error controller reads as follows::
     // example.com/src/Calendar/Controller/ErrorController.php
     namespace Calendar\Controller;
 
-    use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+    use Symfony\Component\ErrorHandler\Exception\FlattenException;
     use Symfony\Component\HttpFoundation\Response;
 
     class ErrorController