minor #1430 [LiveComponent] Fix component syntax error in doc (smnandre)

This PR was squashed before being merged into the 2.x branch.

Discussion
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[LiveComponent] Fix component syntax error in doc

Spotted by `@fGuix` in #1424 (thanks)

Commits
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e3a7325 [LiveComponent] Fix component syntax error in doc

Author: weaverryan

src/LiveComponent/doc/index.rst

@@ -2257,9 +2257,9 @@ Or override the ``loadingContent`` block:
 
 .. code-block:: twig
 
-    {% component SomeHeavyComponent with { defer: true }) }}
+    {% component SomeHeavyComponent with { defer: true } %}
         {% block loadingContent %}Loading...{% endblock %}
-    {{ end_component() }}
+    {% endcomponent %}
 
 To change the initial tag from a ``div`` to something else, use the ``loading-tag`` option: