[form] fix missing use statement for exception UnexpectedTypeException
bug #9236 [Form] fix missing use statement for exception UnexpectedTypeException (jaugustin)

This PR was merged into the master branch.

Discussion
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[Form] fix missing use statement for exception UnexpectedTypeException

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

fix missing use statement for exception `Symfony\Component\Form\Exception\UnexpectedTypeException`

cc @bschussek

Commits
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ea91533 [form] fix missing use statement for exception UnexpectedTypeException