devel/py-tdworkflow: Switch to PEP517 and fix packaging of tests/docs

• Use PEP517 backend instead of legacy distutils.
• Add py-wheel to BUILD_DEPENDS (required for PEP517 builds).
• Patch pyproject.toml to limit setuptools package discovery to tdworkflow* only, excluding tests and docs directories. This prevents installation of non-private top-level directories (tests/, docs/) into ${PYTHONPREFIX_SITELIBDIR}, which previously caused file conflicts with other ports.
• Lower setuptools minimum version to >=63, which matches the version currently available in FreeBSD ports.

PR: 290278
Reported by: se