Bump yt-dlp from 2025.6.30 to 2025.7.21 in /src

Bumps [yt-dlp](https://github.com/yt-dlp/yt-dlp) from 2025.6.30 to 2025.7.21.
- [Release notes](https://github.com/yt-dlp/yt-dlp/releases)
- [Changelog](https://github.com/yt-dlp/yt-dlp/blob/master/Changelog.md)
- [Commits](yt-dlp/yt-dlp@2025.06.30...2025.07.21)

---
updated-dependencies:
- dependency-name: yt-dlp
  dependency-version: 2025.7.21
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/requirements.txt

@@ -1,5 +1,5 @@
 python-telegram-bot[ext]==22.2
 python-dotenv==1.1.1
-yt-dlp==2025.6.30
+yt-dlp==2025.7.21
 gallery-dl==1.29.7
 aiohttp==3.12.14