Bump flake8 from 6.1.0 to 7.0.0 in /client/python

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] <[email protected]>

client/python/pyproject.toml

@@ -9,7 +9,7 @@ license = { text = "Apache Software License" }
 authors = [{ name = "G-Research Open Source Software", email = "[email protected]" }]
 
 [project.optional-dependencies]
-format = ["black==23.7.0", "flake8==6.1.0", "pylint==2.17.5"]
+format = ["black==23.7.0", "flake8==7.0.0", "pylint==2.17.5"]
 # note(JayF): sphinx-jekyll-builder was broken by sphinx-markdown-builder 0.6 -- so pin to 0.5.5
 docs = ["sphinx==7.1.2", "sphinx-jekyll-builder==0.3.0", "sphinx-toolbox==3.2.0b1", "sphinx-markdown-builder==0.5.5"]
 test = ["pytest==7.3.1", "coverage>=6.5.0", "pytest-asyncio==0.21.1"]