fix(deps): upgrade eslint and plugins to 9.39.4 (#201701)

* fix(deps): upgrade eslint and plugins to 10.2.0

* chore: manual lint-fix

* chore: automatic lint-fix

* feat(repo): github actions - lint - use node v24

because it is linting (not runtime), so why not
to use the latest stable Node version

* fix: remove @stylistic/eslint-plugin (in favor of prettier)

* fix: eslint uses `ecmaVersion` 2025

* fix: eslint's "mocha" config is isolated (for test files only)

for example `describe` is not considered "global" outside the
test files. the same for all other "eslint/mocha" rules -
they are applied only to files in `/tests` folder.

* chore: update package-lock.json after eslint upgrade

example.js

@@ -119,6 +119,7 @@ client.on('message', async (msg) => {
             await client.acceptInvite(inviteCode);
             msg.reply('Joined the group!');
         } catch (e) {
+            console.error(e);
             msg.reply('That invite code seems to be invalid.');
         }
     } else if (msg.body.startsWith('!addmembers')) {