Move most of setup.py to pyproject.toml.

The custom setuptools_scm configuration is removed. It was buggy (for
the case of a dirty worktree exactly at the tag, it did not append
`+dirty`) and otherwise is only different from node-and-timestamp by
appending `.dirty` instead of `.dYYYYMMDDHHMMSS`. The latter is
preferable anyway.

pyproject.toml

@@ -1,3 +1,32 @@
 [build-system]
-requires = ["wheel", "setuptools~=62.0", "setuptools_scm"]
+requires = ["wheel", "setuptools~=67.0", "setuptools_scm[toml]>=6.2"]
 build-backend = "setuptools.build_meta"
+
+[project]
+dynamic = ["version", "urls"]
+
+name = "amaranth"
+description = "Amaranth hardware definition language"
+authors = [{name = "Amaranth HDL contributors"}]
+license = {file = "LICENSE.txt"}
+
+requires-python = "~=3.7"
+dependencies = [
+  "importlib_metadata;  python_version<'3.8'", # for __version__ and amaranth._toolchain.yosys
+  "importlib_resources; python_version<'3.9'", # for amaranth._toolchain.yosys
+  "pyvcd>=0.2.2,<0.4", # for amaranth.sim.pysim
+  "Jinja2~=3.0", # for amaranth.build
+]
+
+[project.optional-dependencies]
+# this version requirement needs to be synchronized with the one in amaranth.back.verilog!
+# due to the issue described in https://github.com/pypa/setuptools/issues/3807, this is
+# temporarily pinned to a specific amaranth-yosys version.
+builtin-yosys = ["amaranth-yosys==0.10.0.dev47"]
+remote-build  = ["paramiko~=2.7"]
+
+[project.scripts]
+amaranth-rpc = "amaranth.rpc:main"
+
+[tool.setuptools_scm]
+local_scheme = "node-and-timestamp"

setup.py

@@ -1,25 +1,8 @@
-from setuptools import setup, find_packages
+from setuptools import setup
-
+from setuptools_scm.git import parse as parse_git
-
-def scm_version():
-    def local_scheme(version):
-        if version.tag and not version.distance:
-            return version.format_with("")
-        else:
-            return version.format_choice("+{node}", "+{node}.dirty")
-    return {
-        "relative_to": __file__,
-        "version_scheme": "guess-next-dev",
-        "local_scheme": local_scheme
-    }
 
 
 def doc_version():
-    try:
-        from setuptools_scm.git import parse as parse_git
-    except ImportError:
-        return ""
-
     git = parse_git(".")
     if not git:
         return ""
@@ -30,31 +13,8 @@ def doc_version():
 
 
 setup(
-    name="amaranth",
-    use_scm_version=scm_version(),
-    author="Amaranth HDL contributors",
-    description="Amaranth hardware definition language",
-    #long_description="""TODO""",
-    license="BSD",
-    python_requires="~=3.7",
-    install_requires=[
-        "importlib_metadata; python_version<'3.8'",  # for __version__ and amaranth._toolchain.yosys
-        "importlib_resources; python_version<'3.9'", # for amaranth._toolchain.yosys
-        "pyvcd>=0.2.2,<0.4", # for amaranth.pysim
-        "Jinja2~=3.0",  # for amaranth.build
-    ],
-    extras_require={
-        # this version requirement needs to be synchronized with the one in amaranth.back.verilog!
-        "builtin-yosys": ["amaranth-yosys>=0.10.*"],
-        "remote-build": ["paramiko~=2.7"],
-    },
-    packages=find_packages(exclude=("tests", "tests.*")),
-    entry_points={
-        "console_scripts": [
-            "amaranth-rpc = amaranth.rpc:main",
-        ]
-    },
     project_urls={
+        "Homepage": "https://amaranth-lang.org/",
         "Documentation": "https://amaranth-lang.org/docs/amaranth/{}".format(doc_version()),
         "Source Code": "https://github.com/amaranth-lang/amaranth",
         "Bug Tracker": "https://github.com/amaranth-lang/amaranth/issues",