Migrate pyproject.toml to PEP 621-compliant [project] metadata format.

Squashed commit of the following:

commit 3f939aa095fa6b5feb72fd0367140f1b95dff5ad
Author: Martin Mahner <martin@mahner.org>
Date:   Tue Jul 22 12:38:31 2025 +0200

    Update changelog

commit 938e5e9ebcfbb262447fede565c995759da32b34
Author: Martin Mahner <martin@mahner.org>
Date:   Tue Jul 22 12:35:37 2025 +0200

    Add additional project urls

commit 0e2e576
Merge: 9932218 e19eddd
Author: Martin Mahner <martin@mahner.org>
Date:   Tue Jul 22 12:24:52 2025 +0200

    Merge remote-tracking branch 'origin/main' into project

commit 9932218
Author: Miro Hrončok <miro@hroncok.cz>
Date:   Sun May 11 09:58:11 2025 +0200

    Use standardized [project] table in pyproject.toml

    This allows us to swap the build backend more easily in RHEL, where we don't have poetry-code.

    This requires poetry-core >= 2 because older poetry did not support this.

    Also, replace the value of the license text with a SPDX identifier as documented in
    https://python-poetry.org/docs/pyproject/#license
    Otherwise, poetry-core injects a `Other/Proprietary License` classifier.
    (Note that poetry-core does not yet support PEP 639 fully).

    This change creates s slight change in the metadata, comments inline.

        --- old/qrcode-8.2-py3-none-any/qrcode-8.2.dist-info/METADATA
        +++ new/qrcode-8.2-py3-none-any/qrcode-8.2.dist-info/METADATA
        @@ -2,16 +2,15 @@
         Name: qrcode
         Version: 8.2
         Summary: QR Code image generator
        -License: BSD
        +License: BSD-3-Clause

    This was intentional.

         Keywords: qr,denso-wave,IEC18004
         Author: Lincoln Loop
         Author-email: info@lincolnloop.com
        -Requires-Python: >=3.9,<4.0
        +Requires-Python: ~=3.9

    This is identical in reality.

         Classifier: Development Status :: 5 - Production/Stable
        -Classifier: Intended Audience :: Developers

    This only changes order :/

         Classifier: License :: OSI Approved :: BSD License
        -Classifier: License :: Other/Proprietary License

    This is intentional.

         Classifier: Operating System :: OS Independent
        +Classifier: Intended Audience :: Developers

    See above, order only.

         Classifier: Programming Language :: Python
         Classifier: Programming Language :: Python :: 3
         Classifier: Programming Language :: Python :: 3.9
        @@ -26,8 +25,10 @@
         Provides-Extra: pil
         Provides-Extra: png
         Requires-Dist: colorama ; sys_platform == "win32"
        -Requires-Dist: pillow (>=9.1.0) ; extra == "pil" or extra == "all"
        -Requires-Dist: pypng ; extra == "png" or extra == "all"
        +Requires-Dist: pillow (>=9.1.0) ; extra == "all"
        +Requires-Dist: pillow (>=9.1.0) ; extra == "pil"
        +Requires-Dist: pypng ; extra == "all"
        +Requires-Dist: pypng ; extra == "png"

    This is identical.

         Project-URL: Homepage, https://github.com/lincolnloop/python-qrcode
         Description-Content-Type: text/x-rst

Author: bartTC

CHANGES.rst

@@ -5,10 +5,15 @@ Change log
 WIP
 ===
 
-- Allow execution as a Python module (@stefansjs in `#400`_)::
+- Migrate pyproject.toml to PEP 621-compliant [project] metadata format.
+  (hroncok in `#399`_)
+- Allow execution as a Python module. (stefansjs in `#400`_)
+
+  ::
 
     python -m qrcode --output qrcode.png "hello world"
 
+.. _#399: https://github.com/lincolnloop/python-qrcode/pull/399
 .. _#400: https://github.com/lincolnloop/python-qrcode/pull/400
 
 8.2 (01 May 2025)

pyproject.toml

@@ -1,16 +1,16 @@
 [build-system]
-requires = ["poetry-core"]
+requires = ["poetry-core>=2"]
 build-backend = "poetry.core.masonry.api"
 
-[tool.poetry]
+[project]
 name = "qrcode"
 version = "8.2"
-packages = [{include = "qrcode"}]
 description = "QR Code image generator"
-authors = ["Lincoln Loop <info@lincolnloop.com>"]
-license = "BSD"
-readme = ["README.rst", "CHANGES.rst"]
-homepage = "https://github.com/lincolnloop/python-qrcode"
+authors = [
+    { name = "Lincoln Loop", email = "info@lincolnloop.com" },
+]
+license = { text = "BSD-3-Clause" }
+dynamic = [ "readme" ]
 keywords = ["qr", "denso-wave", "IEC18004"]
 classifiers = [
     "Development Status :: 5 - Production/Stable",
@@ -28,6 +28,30 @@ classifiers = [
     "Topic :: Multimedia :: Graphics",
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
+requires-python = "~=3.9"
+dependencies = [
+    "colorama; sys_platform == 'win32'",
+]
+
+
+[project.optional-dependencies]
+pil = ["pillow >=9.1.0"]
+png = ["pypng"]
+all = ["pypng", "pillow >=9.1.0"]
+
+[project.urls]
+homepage = "https://github.com/lincolnloop/python-qrcode"
+repository = "https://github.com/lincolnloop/python-qrcode.git"
+documentation = "https://github.com/lincolnloop/python-qrcode#readme"
+changelog = "https://github.com/lincolnloop/python-qrcode/blob/main/CHANGES.rst"
+"Bug Tracker" = "https://github.com/lincolnloop/python-qrcode/issues"
+
+[project.scripts]
+qr = "qrcode.console_scripts:main"
+
+[tool.poetry]
+packages = [{include = "qrcode"}]
+readme = ["README.rst", "CHANGES.rst"]
 
 # There is no support for data files yet.
 # https://github.com/python-poetry/poetry/issues/9519
@@ -36,21 +60,6 @@ classifiers = [
 #     { destination = "share/man/man1", from = [ "doc/qr.1" ] },
 # ]
 
-[tool.poetry.scripts]
-qr = 'qrcode.console_scripts:main'
-
-
-[tool.poetry.dependencies]
-python = "^3.9"
-colorama = {version = "*", platform = "win32"}
-pypng = {version = "*", optional = true}
-pillow = {version = ">=9.1.0", optional = true}
-
-[tool.poetry.extras]
-pil = ["pillow"]
-png = ["pypng"]
-all = ["pypng","pillow"]
-
 [tool.poetry.group.dev.dependencies]
 pytest = {version = "*"}
 pytest-cov = {version = "*"}