chore(l10n): 清理已移除语言入口文案

lib/l10n/app_localizations_zh.dart

@@ -209,9 +209,6 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get preferences => '偏好设置';
 
-  @override
-  String get appLanguage => '应用语言';
-
   @override
   String get followingTab => '关注';
 
@@ -512,12 +509,6 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get chineseCaptions => '简体中文字幕';
 
-  @override
-  String get language => '界面语言';
-
-  @override
-  String get systemLanguage => '跟随系统';
-
   @override
   String get english => 'English';
 
@@ -1228,18 +1219,6 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get searchFailed => '搜索失败，请重试。';
 
-  @override
-  String get languageFilter => '语言';
-
-  @override
-  String get languageChinese => '中文';
-
-  @override
-  String get languageIndonesian => '印尼语';
-
-  @override
-  String get languageEnglish => '英语';
-
   @override
   String searchResultCount(int count) {
     return '$count 个结果';