minor #37219 FrameworkBundle fix incorrect nested arrays in php config (GromNaN)

This PR was merged into the 5.2-dev branch.

Discussion
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FrameworkBundle fix incorrect nested arrays in php config

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix https://github.com/symfony/symfony/pull/37201#discussion_r438652771
| License       | MIT

Commits
-------

20459884d2 Fix invalid syntax

src/Symfony/Bundle/FrameworkBundle/Resources/config/secrets.php

@@ -28,6 +28,6 @@ return static function (ContainerConfigurator $container) {
             ->args([abstract_arg('Decryption env var, set in FrameworkExtension')])
 
         ->set('secrets.local_vault', DotenvVault::class)
-            ->args([[abstract_arg('.env file path, set in FrameworkExtension')]])
+            ->args([abstract_arg('.env file path, set in FrameworkExtension')])
     ;
 };