minor symfony#24466 [DependencyInjection] remove unused fixtures file (xabbuh)

This PR was merged into the 3.3 branch.

Discussion
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[DependencyInjection] remove unused fixtures file

| Q             | A
| ------------- | ---
| Branch?       | 3.3
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

I was wondering why the conflict markers in the `master` branch (see https://github.com/symfony/symfony/blob/b6e9471ded49e698c8c2468be9c1b42c621efeac/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services31.php#L43-L52) did not cause any issues. Turned out that this fixtures file was not used anymore (it was only partially removed in symfony#23022).

Commits
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3702e5f remove unused fixtures file

Author: fabpot