Update certifi requirement from >=2024.7.4 to >=2026.4.22

Updates the requirements on [certifi](https://github.com/certifi/python-certifi) to permit the latest version.
- [Commits](certifi/python-certifi@2024.07.04...2026.04.22)

---
updated-dependencies:
- dependency-name: certifi
  dependency-version: 2026.4.22
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements/base.txt

@@ -2,7 +2,7 @@
 # Multiple entries for the same package (with different version constraints) are grouped together.
 
 aiohttp>=3.13.5
-certifi>=2024.7.4
+certifi>=2026.4.22
 cffi>=2.0.0
 # cheroot 8.5.2 fails to build with modern setuptools due to setuptools_scm_git_archive dependency
 cheroot>=10.0.1