build(deps): bump certifi in /libbeat/tests/system (#40155)

Bumps [certifi](https://github.com/certifi/python-certifi) from 2023.7.22 to 2024.7.4.
- [Commits](certifi/python-certifi@2023.07.22...2024.07.04)

---
updated-dependencies:
- dependency-name: certifi
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

libbeat/tests/system/requirements.txt

@@ -9,7 +9,7 @@ backoff==2.2.1
 backports.ssl-match-hostname==3.5.0.1
 bcrypt==4.1.2
 cached-property==1.4.2
-certifi==2023.7.22
+certifi==2024.7.4
 cffi==1.16.0
 chardet==3.0.4
 charset-normalizer==3.3.2