Bump black in /circleci/images/stylechecker/files/etc

Bumps [black](https://github.com/psf/black) from 24.10.0 to 26.3.1.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@24.10.0...26.3.1)

---
updated-dependencies:
- dependency-name: black
  dependency-version: 26.3.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

circleci/images/stylechecker/files/etc/requirements.txt

@@ -4,7 +4,7 @@
 
 -i https://pypi.python.org/simple
 attrs==25.4.0; python_version >= '3.9'
-black==24.10.0; python_version >= '3.9'
+black==26.3.1; python_version >= '3.9'
 click==8.3.1; python_version >= '3.10'
 flake8==7.3.0; python_version >= '3.9'
 flake8-bugbear==25.11.29; python_version >= '3.10'