chore(l10n): 清理已移除语言入口文案

lib/l10n/app_en.arb

@@ -83,7 +83,6 @@
   "completed": "Completed",
   "noSavedShows": "No shows here yet.",
   "preferences": "Preferences",
-  "appLanguage": "App Language",
   "followingTab": "Following",
   "animatedTab": "Animated",
   "recommendedTab": "Recommended",
@@ -245,8 +244,6 @@
   "captionsOff": "Captions off",
   "englishCaptions": "English captions",
   "chineseCaptions": "Chinese captions",
-  "language": "Language",
-  "systemLanguage": "System",
   "english": "English",
   "simplifiedChinese": "简体中文",
   "bahasaIndonesia": "Bahasa Indonesia",
@@ -534,10 +531,6 @@
   "qualityAuto": "Auto",
   "qualityAutoHint": "HLS adjusts the bitrate automatically for your connection.",
   "searchFailed": "Search failed. Please try again.",
-  "languageFilter": "Language",
-  "languageChinese": "Chinese",
-  "languageIndonesian": "Indonesian",
-  "languageEnglish": "English",
   "searchResultCount": "{count} results",
   "@searchResultCount": { "placeholders": { "count": { "type": "int" } } }
 }