Motivation for this change

@flokli requested in #51634 to have a look on shiboken. I was still using Python 3.6 and it was working, so I had a look and noticed that shiboken was patched for Python 3.5 and 3.6. This PR extends the same patch use for 3.7, as well.

I have not run nix-review (I must start doing so), but I have built and run successfully the spyder application that @flokli mentioned on the previous PR. (P.S.: spyder could get updated to a newer version, but hopefully someone else can take it from here.)

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.