Add support for Home Assistant voice (whisper + piper + cloud llm) and Music Assistant via Spotify by librespot

Music assistant has custom modifications they made to librespot that they haven't bothered to even try to upstream.
Thus, they require a custom librespot.  I tried and tried and tried and tried to just override the one already in nixpkgs
but I had trouble doing so despite copying the pattern already shown in nixpkgs for overriding the src of a cargo pkg
(See mopidy) but it just didn't work... Oh well. So I just patch nixpkgs instead with the new source. It works I guess.

This is about where I gave up...

```nix
nixpkgs.overlays = [
  (final: prev: {
    # Cannot use librespot upstream because music-assistant requires custom changes
    # that they never bothered to even try to uptream
    librespot = prev.librespot.overrideAttrs (oldAttrs: rec {
      src = prev.fetchFromGitHub {
        owner = "music-assistant";
        repo = "librespot";
        rev = "786cc46199e583f304a84c786acb0a9b37bc3fbd";
        sha256 = "sha256-xaOrqC8yCjF23Tz31RD3CzqZ3xxrDM6ncW1yoovEaGQ=";
      };

      cargoDeps = oldAttrs.cargoDeps.overrideAttrs (oldAttrs': {
        vendorStaging = oldAttrs'.vendorStaging.overrideAttrs {
          outputHash = "sha256-SqvJSHkyd1IicT6c4pE96dBJNNodULhpyG14HRGVWCk=";
        };
      });
    });
  })
];
```

flake.nix

@@ -120,6 +120,10 @@
                 patches = [
                   # ./patches/gamepadui.patch
                   ./patches/dont-break-nix-serve.patch
+                  # music-assistant needs a specific custom version of librespot
+                  # I tried to use an overlay but my attempts to override the rust package did not work out
+                  # despite me following guides and examples specific to rust packages.
+                  ./patches/librespot-pin.patch
                 ];
               };
               patchedNixpkgs = nixpkgs.lib.fix (self: (import "${patchedNixpkgsSrc}/flake.nix").outputs { self = nixpkgs; });