minor #32323 [FrmaeworkBundle] More simplifications in the DI configuration (javiereguiluz)

This PR was merged into the 4.3 branch.

Discussion
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[FrmaeworkBundle] More simplifications in the DI configuration

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | -
| License       | MIT
| Doc PR        | not needed

This is the continuation of #32322 for the 4.3 branch.

Commits
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fa6ae8ce50 [FrmaeworkBundle] More simplifications in the DI configuration

Author: fabpot

DependencyInjection/Configuration.php

@@ -339,10 +339,7 @@ private function addWorkflowSection(ArrayNodeDefinition $rootNode)
                                         ->defaultNull()
                                     ->end()
                                     ->arrayNode('initial_marking')
-                                        ->beforeNormalization()
-                                            ->ifTrue(function ($v) { return !\is_array($v); })
-                                            ->then(function ($v) { return [$v]; })
-                                        ->end()
+                                        ->beforeNormalization()->castToArray()->end()
                                         ->defaultValue([])
                                         ->prototype('scalar')->end()
                                     ->end()