BuildRequire pyproject-rpm-macros explicitly
Since this package does not use %pyproject_buildrequires and is included in ELN, manual BuildRequires for pyproject-rpm-macros is necessary.
In ELN, the dependency on pyproject-rpm-macros is generated by %pyproject_buildrequires only, the package is not pulled in via python3-devel.
This is new since pyproject-rpm-macros 1.6.0