Update flake8-builtins requirement in /requirements

Updates the requirements on [flake8-builtins](https://github.com/gforcada/flake8-builtins) to permit the latest version.
- [Release notes](https://github.com/gforcada/flake8-builtins/releases)
- [Changelog](https://github.com/gforcada/flake8-builtins/blob/master/CHANGES.rst)
- [Commits](gforcada/flake8-builtins@1.5.0...2.1.0)

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

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

requirements/development.txt

@@ -3,7 +3,7 @@
 
 black
 flake8>=3.8,<4.1
-flake8-builtins>=1.5,<1.6
+flake8-builtins>=1.5,<2.2
 flake8-eradicate>=1.0,<1.5
 flake8-isort>=4.0,<4.3
 pre-commit>=2.12,<2.21