chore: update eslint, enable more rules and fix their findings (#39438)

Update eslint and its plugins, enable more rules and fix their findings:

1. `unicorn/no-unsafe-string-replacement` found that uploading a file
whose name contains `$&` inserted a broken markdown link, because
`String#replace` expands such patterns in the replacement string
2. `@typescript-eslint/require-await` removes `async` from functions
that never await
3. Plugin rules not covered by a preset are now listed explicitly

---------

Co-authored-by: bircni <bircni@icloud.com>

web_src/js/features/admin/common.ts

@@ -289,7 +289,7 @@ function initAdminNotice() {
   const checkboxes = document.querySelectorAll<HTMLInputElement>('.select.table .ui.checkbox input');
 
   queryElems(pageContent, '.select.action', (el) => el.addEventListener('click', () => {
-    switch (el.getAttribute('data-action')) {
+    switch (el.getAttribute('data-action')!) {
       case 'select-all':
         for (const checkbox of checkboxes) {
           checkbox.checked = true;