bug #30548 Correct language code for ukrainian language (stanleyk)

This PR was merged into the 3.4 branch.

Discussion
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Correct language code for ukrainian language

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Correct language code for [ukrainian language](https://en.wikipedia.org/wiki/Ukrainian_language) is **uk**, not **ua**. Similar bug was earlier addressed in #5972, but somehow it appeared here again. Possible BC break in case someone relies on "ua" version being present, but I think that is a minor problem.

Commits
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b86fa93 Correct language code for ukrainian language in security translations.