[Validator] Removed duplicated test for IBAN in data provider

Working on #9850, I spotted a duplicated value on `getValidIbans` data provider and I just removed the duplicated value.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -