minor #28767 [Validator] Add a missing translation (jakzal)

This PR was merged into the 2.8 branch.

Discussion
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[Validator] Add a missing translation

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? |no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

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Commits
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9d70e22794 [Validator] Add a missing translation

src/Symfony/Component/Validator/Resources/translations/validators.pl.xlf

@@ -318,6 +318,10 @@
                 <source>Error</source>
                 <target>Błąd</target>
             </trans-unit>
+            <trans-unit id="83">
+                <source>This is not a valid UUID.</source>
+                <target>To nie jest poprawne UUID.</target>
+            </trans-unit>
         </body>
     </file>
 </xliff>