Apply updates from cookiecutter

This automated commit applies the latest updates from our cookiecutters [1] to
this repo.

[1]: https://github.com/hypothesis/cookiecutters

.cookiecutter/includes/pyproject.toml/dependencies

@@ -0,0 +1 @@
+"python-dotenv",

.cookiecutter/includes/pyproject.toml/tail

@@ -0,0 +1,2 @@
+[project.entry-points.tox]
+tox-envfile = "tox_envfile"

pyproject.toml

@@ -2,8 +2,31 @@
 requires = ["setuptools>=45", "setuptools_scm[toml]>=6.2"]
 build-backend = "setuptools.build_meta"
 
+[project]
+dynamic = ["version"]
+name = "tox-envfile"
+description = "Load env files in your tox envs."
+readme = "README.md"
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "License :: OSI Approved :: BSD License",
+    "Intended Audience :: Developers",
+]
+requires-python = ">=3.9"
+dependencies = [
+    "python-dotenv",
+]
+
+[project.urls]
+Repository = "https://github.com/hypothesis/tox-envfile"
+Issues = "https://github.com/hypothesis/tox-envfile/issues"
+Changelog = "https://github.com/hypothesis/tox-envfile/releases"
 [tool.setuptools_scm]
 
+
+[project.entry-points.tox]
+tox-envfile = "tox_envfile"
+
 [tool.pytest.ini_options]
 addopts = "-q"
 filterwarnings = [

setup.cfg

@@ -1,32 +1,3 @@
-[metadata]
-name = tox-envfile
-description = Load env files in your tox envs.
-long_description = file: README.md
-long_description_content_type = text/markdown
-url = https://github.com/hypothesis/tox-envfile
-project_urls =
-    Bug Tracker = https://github.com/hypothesis/tox-envfile/issues
-    Changelog = https://github.com/hypothesis/tox-envfile/releases
-classifiers =
-    Programming Language :: Python :: 3
-    License :: OSI Approved :: BSD License
-    Intended Audience :: Developers
-
-[options]
-package_dir =
-    = src
-packages = find:
-python_requires = >=3.9
-install_requires =
-    python-dotenv
-
-[options.packages.find]
-where = src
-
-[options.entry_points]
-tox =
-    tox-envfile = tox_envfile
-
 [pycodestyle]
 ignore =
     # Disable pycodestyle errors and warnings that we don't care about because