Refactor localization keys for "neighbors" terminology across multiple languages

- Updated localization keys from "neighbours" to "neighbors" in the following files:
  - app_localizations_bg.dart
  - app_localizations_de.dart
  - app_localizations_en.dart
  - app_localizations_es.dart
  - app_localizations_fr.dart
  - app_localizations_it.dart
  - app_localizations_nl.dart
  - app_localizations_pl.dart
  - app_localizations_pt.dart
  - app_localizations_ru.dart
  - app_localizations_sk.dart
  - app_localizations_sl.dart
  - app_localizations_sv.dart
  - app_localizations_uk.dart
  - app_localizations_zh.dart
- Updated corresponding ARB files to reflect the changes in keys.
- Renamed the NeighboursScreen to NeighborsScreen in the chat and repeater hub screens for consistency.

lib/screens/repeater_hub_screen.dart

@@ -6,7 +6,7 @@ import 'repeater_status_screen.dart';
 import 'repeater_cli_screen.dart';
 import 'repeater_settings_screen.dart';
 import 'telemetry_screen.dart';
-import 'neighbours_screen.dart';
+import 'neighbors_screen.dart';
 
 class RepeaterHubScreen extends StatelessWidget {
   final Contact repeater;
@@ -174,17 +174,15 @@ class RepeaterHubScreen extends StatelessWidget {
             _buildManagementCard(
               context,
               icon: Icons.group,
-              title: l10n.repeater_neighbours,
-              subtitle: l10n.repeater_neighboursSubtitle,
+              title: l10n.repeater_neighbors,
+              subtitle: l10n.repeater_neighborsSubtitle,
               color: Colors.orange,
               onTap: () {
                 Navigator.push(
                   context,
                   MaterialPageRoute(
-                    builder: (context) => NeighboursScreen(
-                      repeater: repeater,
-                      password: password,
-                    ),
+                    builder: (context) =>
+                        NeighborsScreen(repeater: repeater, password: password),
                   ),
                 );
               },