minor #11703 Require Dotenv component without --dev (bocharsky-bw)

This PR was merged into the 3.4 branch.

Discussion
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Require Dotenv component without --dev

Looks like according to these changes: symfony/recipes#501 - Dotenv component is suggested to be added to `require` section of `composer.json`. Both `symfony/skeleton` and `symfony/website-skeleton` require it on prod

Commits
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3f7594d Require Dotenv component without --dev

Author: javiereguiluz

components/dotenv.rst

@@ -17,7 +17,7 @@ Installation
 
 .. code-block:: terminal
 
-    $ composer require --dev symfony/dotenv
+    $ composer require symfony/dotenv
 
 .. include:: /components/require_autoload.rst.inc