minor #47039 Throw error with debug message when ExpressionLanguage Component is not installed (WebMamba)

This PR was squashed before being merged into the 6.2 branch.

Discussion
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Throw error with debug message when ExpressionLanguage Component is not installed

| Q             | A
| ------------- | ---
| Branch?       | 6.2
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       |
| License       | MIT
| Doc PR        |

When using the ExpressionLanguageSyntax constraints without installing the ExpressionLanguage component you get a random error. This PR throws an exception with a debugging message to suggest you install the expression language component.

Commits
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5e4471a952 Throw error with debug message when ExpressionLanguage Component is not installed

Author: fabpot

Constraints/ExpressionLanguageSyntaxValidator.php

@@ -31,6 +31,10 @@ class ExpressionLanguageSyntaxValidator extends ConstraintValidator
 
     public function __construct(ExpressionLanguage $expressionLanguage = null)
     {
+        if (!class_exists(ExpressionLanguage::class)) {
+            throw new \LogicException(sprintf('The "%s" class requires the "ExpressionLanguage" component. Try running "composer require symfony/expression-language".', self::class));
+        }
+
         $this->expressionLanguage = $expressionLanguage;
     }