Update the Symfony version to install in 7.3 branch

Author: javiereguiluz

setup.rst

@@ -48,10 +48,10 @@ application:
 .. code-block:: terminal
 
     # run this if you are building a traditional web application
-    $ symfony new my_project_directory --version="7.2.x" --webapp
+    $ symfony new my_project_directory --version="7.3.x-dev" --webapp
 
     # run this if you are building a microservice, console application or API
-    $ symfony new my_project_directory --version="7.2.x"
+    $ symfony new my_project_directory --version="7.3.x-dev"
 
 The only difference between these two commands is the number of packages
 installed by default. The ``--webapp`` option installs extra packages to give
@@ -63,12 +63,12 @@ Symfony application using Composer:
 .. code-block:: terminal
 
     # run this if you are building a traditional web application
-    $ composer create-project symfony/skeleton:"7.2.x" my_project_directory
+    $ composer create-project symfony/skeleton:"7.3.x-dev" my_project_directory
     $ cd my_project_directory
     $ composer require webapp
 
     # run this if you are building a microservice, console application or API
-    $ composer create-project symfony/skeleton:"7.2.x" my_project_directory
+    $ composer create-project symfony/skeleton:"7.3.x-dev" my_project_directory
 
 No matter which command you run to create the Symfony application. All of them
 will create a new ``my_project_directory/`` directory, download some dependencies