move e11sync-static to it's own file

pkgs/e11sync-static.nix

@@ -0,0 +1,33 @@
+{
+  self,
+  stdenv,
+  python3,
+  python3Packages,
+  coreutils,
+  zopfli,
+  brotli,
+  findutils,
+  dart-sass,
+}:
+stdenv.mkDerivation {
+  name = "e11sync-static";
+  src = self;
+  nativeBuildInputs = [
+    python3Packages.django_5
+    python3Packages.django-compressor
+    dart-sass
+  ];
+  buildPhase = ''
+    mkdir -p static
+    export E11SYNC_STATIC_ROOT=static
+    export E11SYNC_DEBUG=
+    export E11SYNC_COMPRESS_OFFLINE=1
+    ${python3}/bin/python3 ${self}/app/manage.py collectstatic
+    ${python3}/bin/python3 ${self}/app/manage.py compress
+
+    ${findutils}/bin/find static/CACHE -name '*.css' | \
+    ${findutils}/bin/xargs -P''$(${coreutils}/bin/nproc) -I{} sh -c \
+    "${zopfli}/bin/zopfli {} && ${brotli}/bin/brotli {}"
+  '';
+  installPhase = ''mv static $out'';
+}