Enable stricter Typescript options (#30435)

app/javascript/mastodon/features/emoji/emoji_mart_data_light.ts

@@ -29,7 +29,10 @@ const emojis: Emojis = {};
 
 // decompress
 Object.keys(shortCodesToEmojiData).forEach((shortCode) => {
-  const [_filenameData, searchData] = shortCodesToEmojiData[shortCode];
+  const emojiData = shortCodesToEmojiData[shortCode];
+  if (!emojiData) return;
+
+  const [_filenameData, searchData] = emojiData;
   const [native, short_names, search, unified] = searchData;
 
   emojis[shortCode] = {

app/javascript/mastodon/features/emoji/emoji_unicode_mapping_light.ts

@@ -46,7 +46,10 @@ function processEmojiMapData(
 Object.keys(shortCodesToEmojiData).forEach(
   (shortCode: ShortCodesToEmojiDataKey) => {
     if (shortCode === undefined) return;
-    const [filenameData, _searchData] = shortCodesToEmojiData[shortCode];
+
+    const emojiData = shortCodesToEmojiData[shortCode];
+    if (!emojiData) return;
+    const [filenameData, _searchData] = emojiData;
     filenameData.forEach((emojiMapData) => {
       processEmojiMapData(emojiMapData, shortCode);
     });