Update flake8 requirement from ~=6.1 to ~=7.0

Updates the requirements on [flake8](https://github.com/pycqa/flake8) to permit the latest version.
- [Commits](PyCQA/flake8@6.1.0...7.0.0)

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

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

dev-requirements.txt

@@ -8,7 +8,7 @@ git+https://github.com/dbt-labs/dbt-core.git#egg=dbt-tests-adapter&subdirectory=
 black~=23.12
 bumpversion~=0.6.0
 click~=8.1
-flake8~=6.1;python_version>="3.8"
+flake8~=7.0;python_version>="3.8"
 flaky~=3.7
 freezegun~=1.3
 ipdb~=0.13.13