Bump selenium from 4.20.0 to 4.21.0 in /src/collectors

Bumps [selenium](https://github.com/SeleniumHQ/Selenium) from 4.20.0 to 4.21.0.
- [Release notes](https://github.com/SeleniumHQ/Selenium/releases)
- [Commits](SeleniumHQ/selenium@selenium-4.20.0...selenium-4.21.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/collectors/requirements.txt

@@ -14,6 +14,6 @@ python-dateutil==2.9.0.post0
 python-dotenv==1.0.1
 requests==2.31.0
 schedule==1.2.1
-selenium==4.20.0
+selenium==4.21.0
 slackclient==1.3.2
 tweepy==4.14.0