fix(nix): remove stale packages/shared filter

nix/node_modules.nix

@@ -55,7 +55,6 @@ stdenvNoCC.mkDerivation {
       --filter './packages/opencode' \
       --filter './packages/desktop' \
       --filter './packages/app' \
-      --filter './packages/shared' \
       --frozen-lockfile \
       --ignore-scripts \
       --no-progress