minor #17617 Bump Symfony version (kiler129)

This PR was merged into the 5.4 branch.

Discussion
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Bump Symfony version

Bump described symfony versions based on https://symfony.com/releases

However, overall, shouldn't the docs be changed to direct users to check https://symfony.com/releases instead of hardcoding things like:

> Nowadays this is the ``5.4`` branch. If you are instead documenting a new feature, switch to the first Symfony version that included it, e.g. ``upstream/6.2``.

WDYT?

Commits
-------

804f017 Bump Symfony version

Author: javiereguiluz

contributing/documentation/overview.rst

@@ -112,16 +112,16 @@ memorable name for the new branch (if you are fixing a reported issue, use
 
 .. code-block:: terminal
 
-    $ git checkout -b improve_install_article upstream/4.4
+    $ git checkout -b improve_install_article upstream/5.4
 
 In this example, the name of the branch is ``improve_install_article`` and the
-``upstream/4.4`` value tells Git to create this branch based on the ``4.4``
+``upstream/5.4`` value tells Git to create this branch based on the ``5.4``
 branch of the ``upstream`` remote, which is the original Symfony Docs repository.
 
 Fixes should always be based on the **oldest maintained branch** which contains
-the error. Nowadays this is the ``4.4`` branch. If you are instead documenting a
+the error. Nowadays this is the ``5.4`` branch. If you are instead documenting a
 new feature, switch to the first Symfony version that included it, e.g.
-``upstream/5.4``.
+``upstream/6.2``.
 
 **Step 5.** Now make your changes in the documentation. Add, tweak, reword and
 even remove any content and do your best to comply with the
@@ -155,7 +155,7 @@ changes should be applied:
    :align: center
 
 In this example, the **base fork** should be ``symfony/symfony-docs`` and
-the **base** branch should be the ``4.4``, which is the branch that you selected
+the **base** branch should be the ``5.4``, which is the branch that you selected
 to base your changes on. The **head fork** should be your forked copy
 of ``symfony-docs`` and the **compare** branch should be ``improve_install_article``,
 which is the name of the branch you created and where you made your changes.
@@ -205,7 +205,7 @@ contribution to the Symfony docs:
     # create a new branch based on the oldest maintained version
     $ cd projects/symfony-docs/
     $ git fetch upstream
-    $ git checkout -b my_changes upstream/4.4
+    $ git checkout -b my_changes upstream/5.4
 
     # ... do your changes
 
@@ -254,8 +254,8 @@ into multiple branches, corresponding to the different versions of Symfony itsel
 The latest (e.g. ``5.x``) branch holds the documentation for the development branch of
 the code.
 
-Unless you're documenting a feature that was introduced after Symfony 4.4,
-your changes should always be based on the ``4.4`` branch. Documentation managers
+Unless you're documenting a feature that was introduced after Symfony 5.4,
+your changes should always be based on the ``5.4`` branch. Documentation managers
 will use the necessary Git-magic to also apply your changes to all the active
 branches of the documentation.