Add pyproject.toml

This adds a pyproject.toml file to store configuration metadata for
Ruff, mypy and tox.

amuser/base.py

@@ -4,11 +4,7 @@
 import os
 import re
 import shutil
-
-try:
-    from urllib import parse
-except ImportError:  # above is available in py3+, below is py2.7
-    import urlparse as parse
+from urllib import parse
 
 from . import constants as c
 from . import urls

pyproject.toml

@@ -0,0 +1,39 @@
+[tool.ruff.lint]
+# Rule reference: https://docs.astral.sh/ruff/rules/
+select = [
+  "B",
+  "C4",
+  "E",
+  "F",
+  "I",
+  "UP",
+  "W",
+]
+ignore = [
+  "B904",
+  "E501",
+  "F811",
+  "UP031",
+]
+
+[tool.ruff.lint.isort]
+force-single-line = true
+
+[[tool.mypy.overrides]]
+module = ["features.steps.*"]
+disable_error_code = "no-redef"
+
+[tool.tox]
+legacy_tox_ini = """
+    [tox]
+    skipsdist = True
+    envlist = linting
+
+    [testenv]
+    skip_install = True
+
+    [testenv:linting]
+    basepython = python3
+    deps = pre-commit
+    commands = pre-commit run --all-files --show-diff-on-failure
+"""