* Add _service file to fetch sources from git to allow submodules to be included in tarball.
* Add patches to fix build: cadabra2-cmake-correct-python-variable.patch, cadabra2-use-system-pybind11.patch, cadabra2-link-gmp.patch.
* Drop cadabra2-link-python.patch: upstreamed.
* Drop use of %suse_update_desktop_file: no longer needed.
* Drop appdata file included as Source1, bundled files are now installed correctly.
* Use python-rpm-macros and setup to build with newer pythons on Leap 15.X (does not yet work due to unavailability of python311-sympy and python311-ipykernel on these distros).
OBS-URL: https://build.opensuse.org/package/show/science/cadabra2?expand=0&rev=60
