[Form] Fix #11694 - Enforce options value type check in some form types
bug #11696 [Form] Fix #11694 - Enforce options value type check in some form types (kix)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #11696).

Discussion
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[Form] Fix #11694 - Enforce options value type check in some form types

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11694
| License       | MIT
| Doc PR        | none

`Symfony\Component\Form\Extension\Core\Type\RepeatedType` allowed passing strings as options, which caused problems as in #11694.

Commits
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0af6467 [Form] Fix #11694 - Enforce options value type check in some form types