AAP-85334: Replace Black + Flake8 with Ruff

Migrate Python linting and formatting toolchain from Black (formatter)
and Flake8 (linter) to Ruff, which provides both in a single tool.

- pyproject.toml: remove [tool.black], add [tool.ruff] config sections
- tox.ini: replace black+flake8 deps/commands with ruff in linters env
- awxkit/tox.ini: replace flake8 with ruff in lint env
- Makefile: replace `black` target with `format` + `lint`, keep `black`
  as legacy alias, update `check` and `api-lint`
- pre-commit.sh: use `ruff format --check`, honor AWX_IGNORE_RUFF
- requirements_dev.txt: swap black/flake8 for ruff
- Dockerfile.j2: install ruff instead of black
- CONTRIBUTING.md: update tool references
- Fix noqa comments to use # separator instead of ; (ruff requirement)
- Add noqa: F841 for false positive in awxkit/cli/__init__.py

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

awxkit/tox.ini

@@ -26,11 +26,9 @@ commands =
 [testenv:lint]
 deps =
     {[testenv]deps}
-    flake8
+    ruff
 commands =
-    flake8 awxkit
-# pylama --report report.pylama awxkit
-# py.test awxkit --pylama --junitxml=report.pylama {posargs}
+    ruff check awxkit
     - coverage erase
 
 [testenv:coveralls]
@@ -39,9 +37,6 @@ commands=
     - coverage report -m
     - coveralls
 
-[flake8]
-max-line-length = 120
-
 [pytest]
 addopts = -v --tb=native
 testpaths = test