minor #28675 [CS] Enforces null type hint on last position in phpDocs (carusogabriel)

This PR was merged into the 2.8 branch.

Discussion
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[CS] Enforces null type hint on last position in phpDocs

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | -   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | - <!-- required for new features -->

As a majority in our codebase, the `null` typehint usually comes in the last position in phpDocs.

Commits
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efbba25577 [CS] Enforces null type hint on last position in phpDocs

Author: nicolas-grekas

Translation/PhpStringTokenParser.php

@@ -89,7 +89,7 @@ public static function parse($str)
      * Parses escape sequences in strings (all string types apart from single quoted).
      *
      * @param string      $str   String without quotes
-     * @param null|string $quote Quote type
+     * @param string|null $quote Quote type
      *
      * @return string String with escape sequences parsed
      */