Merge pull request #6614 from ThomasWaldmann/require-setuptools-scm-via-pyproject-1.2

setuptools_scm: also require it via pyproject.toml

pyproject.toml

@@ -1,3 +1,3 @@
 [build-system]
-requires = ["setuptools", "pkgconfig", "Cython"]
+requires = ["setuptools", "pkgconfig", "Cython", "setuptools_scm>=1.7"]
 build-backend = "setuptools.build_meta"