chore(l10n): unmap dropped locales from Crowdin, add uk to setup picker

Follow-up to the arb removal: unmap ar/hi/ko/nl/zh-CN/zh-TW in
crowdin.yml so crowdin pull does not recreate them, trim the dead
entries from both language pickers, and add the missing uk entry to
the setup-screen picker.

lib/screens/settings/appearance_settings_page.dart

@@ -693,18 +693,12 @@ class _LanguageSelector extends StatelessWidget {
     ('es', 'Español', Icons.language),
     ('es_ES', 'Español (España)', Icons.language),
     ('fr', 'Français', Icons.language),
-    ('hi', 'हिन्दी', Icons.language),
     ('ja', '日本語', Icons.language),
-    ('ko', '한국어', Icons.language),
-    ('nl', 'Nederlands', Icons.language),
     ('pt', 'Português', Icons.language),
     ('pt_PT', 'Português (Brasil)', Icons.language),
     ('ru', 'Русский', Icons.language),
     ('tr', 'Türkçe', Icons.language),
     ('uk', 'Українська', Icons.language),
-    ('zh', '简体中文', Icons.language),
-    ('zh_CN', '简体中文 (中国)', Icons.language),
-    ('zh_TW', '繁體中文', Icons.language),
   ];
 
   /// Uses filteredLocaleCodes from supported_locales.dart (generated file).

lib/screens/setup_screen.dart

@@ -709,17 +709,12 @@ class _SetupScreenState extends ConsumerState<SetupScreen> {
     ('es', 'Español', Icons.language),
     ('es_ES', 'Español (España)', Icons.language),
     ('fr', 'Français', Icons.language),
-    ('hi', 'हिन्दी', Icons.language),
     ('ja', '日本語', Icons.language),
-    ('ko', '한국어', Icons.language),
-    ('nl', 'Nederlands', Icons.language),
     ('pt', 'Português', Icons.language),
     ('pt_PT', 'Português (Brasil)', Icons.language),
     ('ru', 'Русский', Icons.language),
     ('tr', 'Türkçe', Icons.language),
-    ('zh', '简体中文', Icons.language),
-    ('zh_CN', '简体中文 (中国)', Icons.language),
-    ('zh_TW', '繁體中文', Icons.language),
+    ('uk', 'Українська', Icons.language),
   ];
 
   List<(String, String, IconData)> get _filteredLanguages {