minor #17555 [Validator] replace expressionLanguageSyntax with new expressionSyntax (MrYamous)

This PR was merged into the 6.1 branch.

Discussion
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[Validator] replace expressionLanguageSyntax with new expressionSyntax

As expressionSyntax deprecates expressionLanguageSyntax, replace it from constraint's list

[Related code PR](symfony/symfony#45623)

Commits
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3a35ff2 validator - replace expressionLanguageSyntax with new expressionSyntax

Author: javiereguiluz

reference/constraints.rst

@@ -14,7 +14,6 @@ Validation Constraints Reference
    constraints/Type
 
    constraints/Email
-   constraints/ExpressionLanguageSyntax (deprecated)
    constraints/ExpressionSyntax
    constraints/Length
    constraints/Url

reference/constraints/map.rst.inc

@@ -16,7 +16,7 @@ String Constraints
 ~~~~~~~~~~~~~~~~~~
 
 * :doc:`Email </reference/constraints/Email>`
-* :doc:`ExpressionLanguageSyntax </reference/constraints/ExpressionLanguageSyntax>`
+* :doc:`ExpressionSyntax </reference/constraints/ExpressionSyntax>`
 * :doc:`Length </reference/constraints/Length>`
 * :doc:`Url </reference/constraints/Url>`
 * :doc:`Regex </reference/constraints/Regex>`