minor #16075 Update setup.rst for V5.4 (BahmanMD)

This PR was merged into the 5.4 branch.

Discussion
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Update setup.rst for V5.4

Creating the correct command and fixing the installation problem of version 5.4

Commits
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d92e0f8 Update setup.rst for V5.4

Author: javiereguiluz

setup.rst

@@ -54,10 +54,10 @@ application:
 .. code-block:: terminal
 
     # run this if you are building a traditional web application
-    $ symfony new my_project_name --version=next --full
+    $ symfony new my_project_name --version="5.4.x@dev" --full
 
     # run this if you are building a microservice, console application or API
-    $ symfony new my_project_name --version=next
+    $ symfony new my_project_name --version="5.4.x@dev"
 
 The only difference between these two commands is the number of packages
 installed by default. The ``--full`` option installs all the packages that you