[Serializer] Fix CS. Uniformize PHPDoc.
minor #12102 minor [Serializer] Fix CS. Uniformize PHPDoc. (dunglas)

This PR was merged into the 2.6-dev branch.

Discussion
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minor [Serializer] Fix CS. Uniformize PHPDoc.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT

Commits
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5be84c4 [Serializer] Fix CS. Uniformize PHPDoc.