minor #11440 Fix format by removing underscore (dominikhajduk)

This PR was merged into the 4.2 branch.

Discussion
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Fix format by removing underscore

Please see link in second point in: https://symfony.com/doc/current/messenger.html#middleware

Commits
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ebd1544 Fix format by removing underscore

Author: javiereguiluz

messenger.rst

@@ -433,7 +433,7 @@ for each bus looks like this:
 #. ``logging`` middleware. Responsible for logging the beginning and the end of the
    message within the bus;
 
-#. _Your own collection of middleware_;
+#. Your own collection of middleware_;
 
 #. ``send_message`` middleware. Will route the messages you configured to their
    corresponding sender and stop the middleware chain;