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=";
        };
      });
    });
  })
];
```

patches/librespot-pin.patch

@@ -0,0 +1,28 @@
+diff --git a/pkgs/applications/audio/librespot/default.nix b/pkgs/applications/audio/librespot/default.nix
+index 9694c3d0cf4f..ca9502de7ee1 100644
+--- a/pkgs/applications/audio/librespot/default.nix
++++ b/pkgs/applications/audio/librespot/default.nix
+@@ -25,14 +25,19 @@ rustPlatform.buildRustPackage rec {
+   version = "0.6.0";
+ 
+   src = fetchFromGitHub {
+-    owner = "librespot-org";
++    owner = "googlebot42";
+     repo = "librespot";
+-    rev = "v${version}";
+-    sha256 = "sha256-dGQDRb7fgIkXelZKa+PdodIs9DxbgEMlVGJjK/hU3Mo=";
++    rev = "786cc46199e583f304a84c786acb0a9b37bc3fbd";
++    sha256 = "sha256-xaOrqC8yCjF23Tz31RD3CzqZ3xxrDM6ncW1yoovEaGQ=";
+   };
+ 
+   useFetchCargoVendor = true;
+-  cargoHash = "sha256-SqvJSHkyd1IicT6c4pE96dBJNNodULhpyG14HRGVWCk=";
++  cargoHash = "sha256-sUAZgOuBD9CGAy1mRqLRzVnVfxB0DqSCNAc2yzItTCA=";
++
++  cargoBuildFlags = [
++    "--features"
++    "passthrough-decoder"
++  ];
+ 
+   nativeBuildInputs = [
+     pkg-config