Update emoji data for Unicode 16 (#36596)

Use emoji data from https://github.com/github/gemoji/pull/303 because
`github/gemoji` is unmaintained.

`assets/emoji.json` is now pretty-printed so that future diffs will
actually be readable. This causes no isses as the only place where it is
used is in frontend which imports it via `with {type: 'json'}` where
whitespace is irrelevant.

<img width="205" height="75" alt="image"
src="https://github.com/user-attachments/assets/96e335b8-acf6-4996-ace4-824c0870a7d3"
/>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

web_src/js/utils/match.test.ts

@@ -1,47 +1,59 @@
 import {matchEmoji, matchMention} from './match.ts';
 
 test('matchEmoji', () => {
-  expect(matchEmoji('')).toEqual([
-    '+1',
-    '-1',
-    '100',
-    '1234',
-    '1st_place_medal',
-    '2nd_place_medal',
-  ]);
+  expect(matchEmoji('')).toMatchInlineSnapshot(`
+    [
+      "+1",
+      "-1",
+      "100",
+      "1234",
+      "1st_place_medal",
+      "2nd_place_medal",
+    ]
+  `);
 
-  expect(matchEmoji('hea')).toEqual([
-    'headphones',
-    'headstone',
-    'health_worker',
-    'hear_no_evil',
-    'heard_mcdonald_islands',
-    'heart',
-  ]);
+  expect(matchEmoji('hea')).toMatchInlineSnapshot(`
+    [
+      "head_shaking_horizontally",
+      "head_shaking_vertically",
+      "headphones",
+      "headstone",
+      "health_worker",
+      "hear_no_evil",
+    ]
+  `);
 
-  expect(matchEmoji('hear')).toEqual([
-    'hear_no_evil',
-    'heard_mcdonald_islands',
-    'heart',
-    'heart_decoration',
-    'heart_eyes',
-    'heart_eyes_cat',
-  ]);
+  expect(matchEmoji('hear')).toMatchInlineSnapshot(`
+    [
+      "hear_no_evil",
+      "heard_mcdonald_islands",
+      "heart",
+      "heart_decoration",
+      "heart_eyes",
+      "heart_eyes_cat",
+    ]
+  `);
 
-  expect(matchEmoji('poo')).toEqual([
-    'poodle',
-    'hankey',
-    'spoon',
-    'bowl_with_spoon',
-  ]);
+  expect(matchEmoji('poo')).toMatchInlineSnapshot(`
+    [
+      "poodle",
+      "hankey",
+      "spoon",
+      "bowl_with_spoon",
+    ]
+  `);
 
-  expect(matchEmoji('1st_')).toEqual([
-    '1st_place_medal',
-  ]);
+  expect(matchEmoji('1st_')).toMatchInlineSnapshot(`
+    [
+      "1st_place_medal",
+    ]
+  `);
 
-  expect(matchEmoji('jellyfis')).toEqual([
-    'jellyfish',
-  ]);
+  expect(matchEmoji('jellyfis')).toMatchInlineSnapshot(`
+    [
+      "jellyfish",
+    ]
+  `);
 });
 
 test('matchMention', () => {