[HttpKernel] fixed unit tests when using phpunit.phar
minor #10369 [HttpKernel] fixed unit tests when using phpunit.phar (fabpot)

This PR was merged into the 2.4 branch.

Discussion
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[HttpKernel] fixed unit tests when using phpunit.phar

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

Commits
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0edb192 [HttpKernel] fixed unit tests when using phpunit.phar