fuchsia: Remove dead flutter_frontend_server code (#19500)

flutter_frontend_server/BUILD.gn

@@ -4,50 +4,6 @@
 
 import("//third_party/dart/utils/application_snapshot.gni")
 
-# TODO(kaushikiska@): Leaving this here to make it a soft-transition
-# Remove this once we no longer need engine sources in fuchsia/topaz.
-if (is_fuchsia_host || is_fuchsia) {
-  import("//build/dart/dart_library.gni")
-  import("//build/dart/dart_tool.gni")
-
-  dart_library("flutter_frontend_server") {
-    disable_analysis = true
-    package_name = "flutter_frontend_server"
-
-    sources = [
-      "server.dart",
-    ]
-
-    deps = [
-      "//third_party/dart-pkg/pub/args",
-      "//third_party/dart-pkg/pub/cli_util",
-      "//third_party/dart-pkg/pub/path",
-      "//third_party/dart-pkg/pub/source_maps",
-      "//third_party/dart-pkg/pub/usage",
-      "//third_party/dart/pkg/analyzer",
-      "//third_party/dart/pkg/build_integration",
-      "//third_party/dart/pkg/dev_compiler",
-      "//third_party/dart/pkg/front_end",
-      "//third_party/dart/pkg/frontend_server",
-      "//third_party/dart/pkg/kernel",
-      "//third_party/dart/pkg/vm",
-    ]
-  }
-
-  dart_tool("frontend_server_tool") {
-    main_dart = "bin/starter.dart"
-    source_dir = "."
-    disable_analysis = true
-    output_name = "frontend_server"
-
-    sources = []
-
-    deps = [
-      ":flutter_frontend_server",
-    ]
-  }
-}
-
 frontend_server_files =
     exec_script("//third_party/dart/tools/list_dart_files.py",
                 [