Bump flake8 from 6.1.0 to 7.0.0

Bumps [flake8](https://github.com/pycqa/flake8) from 6.1.0 to 7.0.0.
- [Commits](PyCQA/flake8@6.1.0...7.0.0)

---
updated-dependencies:
- dependency-name: flake8
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -1,6 +1,6 @@
 cairosvg==2.7.1
 click==8.1.7
-flake8==6.1.0
+flake8==7.0.0
 Jinja2==3.1.2
 MarkupSafe==2.1.3
 mike==2.0.0