minor #24342 removed useless PHPDoc (OskarStark)
minor #24342 removed useless PHPDoc (OskarStark)

This PR was squashed before being merged into the 2.7 branch (closes #24342).

Discussion
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removed useless PHPDoc

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no <!-- don't forget updating src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | no <!-- don't forget updating UPGRADE-*.md files -->
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        | n/a

Commits
-------

5ee9043d8b removed useless PHPDoc

symfony/Serializer,symfony/serializer