Added SK translations
minor #11271 [Validator] Added missing Slovak translations (pulzarraider)

This PR was submitted for the master branch but it was merged into the 2.5 branch instead (closes #11271).

Discussion
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[Validator] Added missing Slovak translations

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

Commits
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585a045 Added SK translations
fix the return types