[DependencyInjection] Remove duplicate  declaration in PhpDumper
minor #12953 [DependencyInjection] Remove duplicate $parameters declaration in PhpDumper (sjagr)

This PR was squashed before being merged into the 2.5 branch (closes #12953).

Discussion
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[DependencyInjection] Remove duplicate $parameters declaration in PhpDumper

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #12952
| License       | MIT
| Doc PR        |

2.5 breaks on the latest `composer update` without this fix - after applying and manually deleting `app/cache/*`, everything is hunky-dory

Commits
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e3a4cdc [DependencyInjection] Remove duplicate  declaration in PhpDumper