minor symfony#14500 Update to twig/cssinliner-extra (Nyholm)

This PR was merged into the 4.4 branch.

Discussion
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Update to twig/cssinliner-extra

The package twig/cssinliner-extension has been abandoned.

Commits
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46ba359 Update to twig/cssinliner-extra

Author: javiereguiluz

components/mime.rst

@@ -103,12 +103,12 @@ extension:
 
 .. code-block:: terminal
 
-    $ composer require twig/cssinliner-extension
+    $ composer require twig/cssinliner-extra
 
 Now, enable the extension::
 
     // ...
-    use Twig\CssInliner\CssInlinerExtension;
+    use Twig\Extra\CssInliner\CssInlinerExtension;
 
     $loader = new FilesystemLoader(__DIR__.'/templates');
     $twig = new Environment($loader);