bug #37725 [Form] Fix Guess phpdoc return type (franmomu)

This PR was merged into the 3.4 branch.

Discussion
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[Form] Fix Guess phpdoc return type

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | -
| License       | MIT
| Doc PR        | -

Since `Guess` is abstract, `static` represents better the return type, so calling `TypeGuess::getBestGuess()` would return `TypeGuess` instead of `Guess`.

Commits
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27bb1c499d Fix typehint phpdoc

Author: fabpot

Guess/Guess.php

@@ -60,9 +60,9 @@ abstract class Guess
      * If there are multiple guesses with the same, highest confidence, the
      * returned guess is any of them.
      *
-     * @param Guess[] $guesses An array of guesses
+     * @param static[] $guesses An array of guesses
      *
-     * @return self|null
+     * @return static|null
      */
     public static function getBestGuess(array $guesses)
     {