chore(deps): bump discord.js from 14.14.1 to 14.15.3

Bumps [discord.js](https://github.com/discordjs/discord.js/tree/HEAD/packages/discord.js) from 14.14.1 to 14.15.3.
- [Release notes](https://github.com/discordjs/discord.js/releases)
- [Changelog](https://github.com/discordjs/discord.js/blob/main/packages/discord.js/CHANGELOG.md)
- [Commits](https://github.com/discordjs/discord.js/commits/14.15.3/packages/discord.js)

---
updated-dependencies:
- dependency-name: discord.js
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

services/nodecg-io-discord/package.json

@@ -37,7 +37,7 @@
         "nodecg-io-tsconfig": "^1.0.0"
     },
     "dependencies": {
-        "discord.js": "^14.14.1",
+        "discord.js": "^14.15.3",
         "nodecg-io-core": "^0.3.0"
     }
 }