Replace black with ruff

black depends on pathspec that is licensed under MPL 2.0. Even though
MPL 2.0 can _maybe_ be included in an ASF project, I'd
prefer to simplify the discussion and just replace black with ruff that
is licensed as Apache 2.0, does not have any dependencies, and is
already used by other Apache projects.

Author: Gerrrr

CONTRIBUTING.md

@@ -32,7 +32,7 @@ See the [poetry docs](https://python-poetry.org/docs) for more.
 
 # Linting and formatting
 
-Code-style is enforced using [black](https://black.readthedocs.io/) and [flake8](https://flake8.pycqa.org/); import optimisation is handled by [isort](https://pycqa.github.io/isort/) and [autoflake](https://pypi.org/project/autoflake/).  Linting is automatically applied when tox runs tests; if linting fails, you can fix trivial problems with:
+Code-style is enforced using [ruff](https://docs.astral.sh/ruff/) and [flake8](https://flake8.pycqa.org/); import optimisation is handled by [isort](https://pycqa.github.io/isort/) and [autoflake](https://pypi.org/project/autoflake/).  Linting is automatically applied when tox runs tests; if linting fails, you can fix trivial problems with:
 
 ```
 ./toxw -e format

poetry.lock

@@ -25,10 +25,10 @@ pg8000 = "^1.31.2"
 pytest = "^6.2.2"
 pytz = "2021.1"
 tox = "^3.25.0"
-black = "^22.3.0"
 flake8 = "^4.0.1"
 autoflake = "^1.4"
 isort = "^5.10.1"
+ruff = "^0.6.9"
 
 [tool.pytest.ini_options]
 filterwarnings = [
@@ -39,7 +39,7 @@ filterwarnings = [
 [tool.poetry.scripts]
 hunter = 'hunter.main:main'
 
-[tool.black]
+[tool.ruff]
 line-length = 100
 
 [tool.isort]

pyproject.toml

@@ -19,20 +19,20 @@ passenv =
     SSH_AUTH_SOCK
 setenv =
     BUILD_DIR = {toxinidir}/build/{envname}
-    BLACK_OPTS =
+    RUFF_OPTS =
     FLAKE8_OPTS = --count --show-source --statistics
     AUTOFLAKE_OPTS = --exclude build --recursive --remove-all-unused-imports
     POETRY_OPTS = -v
     PYTEST_OPTS =
 
     # Linting should be quiet and fast
-    lint: BLACK_OPTS = --quiet --fast
+    lint: RUFF_OPTS = --quiet --fast
     lint: FLAKE8_OPTS =
     lint: POETRY_OPTS = --quiet --no-root
 commands_pre =
     ./poetryw install {env:POETRY_OPTS}
 commands =
-    black {env:BLACK_OPTS} --check --diff .
+    ruff {env:RUFF_OPTS} check --diff .
     autoflake {env:AUTOFLAKE_OPTS} --check .
     isort --check --diff .
     flake8 {env:FLAKE8_OPTS}
@@ -43,7 +43,7 @@ commands =
 # environment
 [testenv:format]
 commands =
-    black .
+    ruff check --fix .
     autoflake {env:AUTOFLAKE_OPTS} --in-place .
     isort .