Update flake8 requirement from <6,>=5 to >=5,<7 in /scripts

Updates the requirements on [flake8](https://github.com/pycqa/flake8) to permit the latest version.
- [Release notes](https://github.com/pycqa/flake8/releases)
- [Commits](PyCQA/flake8@5.0.0...6.0.0)

---
updated-dependencies:
- dependency-name: flake8
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

scripts/requirements-dev.txt

@@ -2,7 +2,7 @@
 
 # Linters
 bandit
-flake8>=5,<6  # flake8-pyi deprecation warnings  #  flake8-quotes doesn't support v6 yet
+flake8>=5,<7  # flake8-pyi deprecation warnings  #  flake8-quotes doesn't support v6 yet
 flake8-builtins
 flake8-bugbear
 flake8-class-attributes-order