libghostty-vt: fix dependency path resolution errors

Zigs build infra computes relatives paths to build-time executables that use `setCwd.`
The logic is purely lexical and doesn't take into account symlinks, unlike `chdir` that follows symlinks.

If the `cwd` resolves to a different depth, then the relative path becomes incorrect.

nix/libghostty-vt.nix

@@ -37,7 +37,23 @@ stdenv.mkDerivation (finalAttrs: {
     );
   };
 
-  deps = callPackage ../build.zig.zon.nix {name = "${finalAttrs.pname}-cache-${finalAttrs.version}";};
+  # Zig's build runner computes relative paths from `cwd` to the build directory.
+  # The logic is purely lexical, so if the `cwd` is a symlink that resolves to a different depth during `chdir`, the computed path becomes incorrect.
+  #
+  # See: https://codeberg.org/ziglang/zig/issues/32121
+  #
+  # Workaround: override `linkFarm` with a copy-farm so deps are real directories, not symlinks.
+  deps = callPackage ../build.zig.zon.nix {
+    name = "${finalAttrs.pname}-cache-${finalAttrs.version}";
+    linkFarm = name: entries:
+      runCommand name {} ''
+        mkdir -p $out
+        ${lib.concatMapStringsSep "\n" (e: ''
+            cp -rL ${e.path} $out/${e.name}
+          '')
+          entries}
+      '';
+  };
 
   nativeBuildInputs =
     [