Upstream restructured the project into a src/ layout built from
pyproject.toml, so the flat mysql_config_coder.py that the port
installed no longer exists and staging failed with "sed:
mysql_config_coder.py: No such file or directory".
Switch to USE_PYTHON=pep517 and take the version from pyproject.toml,
so that the resulting wheel matches the glob in PEP517_INSTALL_CMD.
The distfile is byte-identical, only its name changes.
Drop the py-click run dependency, as upstream now uses argparse, and
relax upstream's uv_build<0.10.0 build backend pin, which rejects
devel/py-uv-build 0.12.15.