minor #20766 FIXED NON EXISTING TYPE DECLARATION (edwinhageman)

This PR was submitted for the master branch but it was merged into the 3.1 branch instead (closes #20766).

Discussion
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FIXED NON EXISTING TYPE DECLARATION

| Q             | A
| ------------- | ---
| Branch?       | 3.1, 3.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #20765
| License       | MIT
| Doc PR        | reference to the documentation PR, if any

Commits
-------

d99234a FIXED NON EXISTING TYPE DECLARATION

src/Symfony/Component/Validator/ConstraintValidator.php

@@ -36,7 +36,7 @@ abstract class ConstraintValidator implements ConstraintValidatorInterface
     const OBJECT_TO_STRING = 2;
 
     /**
-     * @var ExecutionContextInterface2Dot5
+     * @var ExecutionContextInterface
      */
     protected $context;