fix(flake.nix): Don't remove the `.tri` api spec file when building

flake.nix

@@ -99,7 +99,6 @@
         openssl
         lua54Packages.lua
       ];
-
       cargo_toml = craneLib.cleanCargoToml {cargoToml = ./Cargo.toml;};
       pname = cargo_toml.package.name;
 
@@ -107,7 +106,15 @@
       craneBuild = craneLib.buildPackage {
         inherit nativeBuildInputs buildInputs;
 
-        src = craneLib.cleanCargoSource ./.;
+        src = let
+          trixyFilter = path: _type: builtins.match ".*tri$" path != null;
+          markdownOrCargo = path: type:
+            (trixyFilter path type) || (craneLib.filterCargoSources path type);
+        in
+          pkgs.lib.cleanSourceWith {
+            src = craneLib.path ./.;
+            filter = markdownOrCargo;
+          };
 
         doCheck = true;
       };