adapt to new python cmake setup

comment out CMP0087 NEW cmake policy because it fails on some CI runners

Fix CI yml file - the 2.7 test will not work anymore

CMakeLists.txt

@@ -29,7 +29,6 @@ add_subdirectory(cmake/modules)
 # if Python bindings are enabled, include necessary sub directories.
 if( DUNE_ENABLE_PYTHONBINDINGS )
   add_subdirectory(python)
-  dune_python_install_package(PATH python)
 endif()
 
 # finalize the dune project, e.g. generating config.h etc.

python/CMakeLists.txt

 add_subdirectory(dune)
 
-configure_file(setup.py.in setup.py)
+dune_python_install_package(
+  PATH "."                                           # relative path containing the package
+  DEPENDS _vtk
+  CMAKE_METADATA_FILE dune/vtk/metadata.cmake        # metadata file to generate
+  CMAKE_METADATA_FLAGS DUNE_OPTS_FILE
+)
+# cmake_policy(SET CMP0087 NEW)

python/dune/__init__.py

-__import__('pkg_resources').declare_namespace(__name__)

python/dune/vtk/CMakeLists.txt

@@ -3,3 +3,6 @@ add_python_targets(vtk
 )
 dune_add_pybind11_module(NAME _vtk)
 set_property(TARGET _vtk PROPERTY LINK_LIBRARIES dunecommon dunegeometry dunegrid dunevtk APPEND)
+if(SKBUILD)
+  install(TARGETS _vtk LIBRARY DESTINATION python/dune/vtk)
+endif()

python/setup.py.in

-from setuptools import setup, find_packages
-
-pkg = [m for m in "${ProjectPythonRequires}".split(' ') if "dune" not in m]
-
-setup(name="${ProjectName}",
-    namespace_packages=['dune'],
-    description="${ProjectDescription}",
-    version="${ProjectVersionString}",
-    author="${ProjectAuthor}",
-    author_email="${ProjectMaintainerEmail}",
-    packages = find_packages(),
-    zip_safe = 0,
-    package_data = {'': ['*.so']},
-    install_requires = pkg
-  )