supercollider: fix Qt wrapping

[OPNA2608]

Don't know how to use this package, but it launches. I've only wrapped the binaries that depend on Qt.

Motivation for this change

#116548, cc @turion

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• 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 nixpkgs-review --run "nixpkgs-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)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 117333 at 731ab0b6 run on x86_64-linux 1

5 packages built successfully:

• python38Packages.foxdot
• python39Packages.foxdot
• sonic-pi
• supercollider
• supercollider_scel

[turion]

Thanks :) It can be tightened in two places:

1. It seems like dontWrapQtApps can be removed completely, and the postFixup phase removed
2. In all-packages.nix, it should say libsForQt5 instead of libsForQt514 I think.

[OPNA2608]

2. In all-packages.nix, it should say libsForQt5 instead of libsForQt514 I think.

That's in the release-20.09 branch, this PR is against master which has libsForQt5.

Edit: The version in release-20.09 is also outdated and apparently incompatible with Qt 5.15, hence the pinning to Qt 5.14. Looks like this bump wasn't backported to stable: #104431

[turion]

1. In all-packages.nix, it should say libsForQt5 instead of libsForQt514 I think.

That's in the release-20.09 branch, this PR is against master which has libsForQt5.

Ah my bad, I was looking at an outdated branch from last year that still had libsForQt514. Then everything is looking great!

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/prs-already-reviewed/2617/363