[fuchsia] Remove duplicate gn_configs and uprev test-scripts

Change https://crrev.com/c/5823950 moved most of the gn_configs to
fuchsia-gn-sdk, and they are not needed to be repeated again in
the gn_configs.gni anymore

Cq-Include-Trybots: luci.dart.try:vm-fuchsia-release-x64-try,vm-fuchsia-release-arm64-try
Bug: http://crbug.com/359657446
Change-Id: I2be62484f2f5279a8804f81714bf0db22ef4384c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/382761
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>

DEPS

@@ -694,7 +694,7 @@ Var("dart_root") + "/third_party/pkg/tar":
     "packages": [
       {
       "package": "chromium/fuchsia/test-scripts",
-      "version": "oGxqx29_HA1eEBnt9pRiZYDa_BkzACC6l3_3xYYKLjYC",
+      "version": "NWpblL_DFACOx_Spi9_s8s3hpYOESpZM4cGiKqUJl1AC",
       }
     ],
     "condition": 'download_fuchsia_deps',
@@ -705,7 +705,7 @@ Var("dart_root") + "/third_party/pkg/tar":
     "packages": [
       {
       "package": "chromium/fuchsia/gn-sdk",
-      "version": "OKGFjciA5Vd0TQks4ow7-ppfxy_Y6v5hSjjn2w6LWjwC",
+      "version": "ALNKvSVWQSpw1uxPyh6OvWHf878FzEm6nvVEyTB8H-8C",
       }
     ],
     "condition": 'download_fuchsia_deps',

build/config/fuchsia/gn_configs.gni

@@ -4,40 +4,9 @@
 
 assert(is_fuchsia)
 
-declare_args() {
-  # Path to the fuchsia SDK. This is intended for use in other templates &
-  # rules to reference the contents of the fuchsia SDK.
-  fuchsia_sdk = "//third_party/fuchsia/sdk/$host_os"
-
-  # ID uniquely identifying the Fuchsia IDK build. This is exposed as a
-  # property so it can be used to locate images and packages on GCS and
-  # as a marker to indicate the "version" of the IDK.
-  # Defaults to the id found in the manifest.json file of the SDK.
-  fuchsia_sdk_id = ""
-}
-
-declare_args() {
-  # The SDK manifest file. This is useful to include as a dependency
-  # for some targets in order to cause a rebuild when the version of the
-  # SDK is changed.
-  fuchsia_sdk_manifest_file = "$fuchsia_sdk/meta/manifest.json"
-
-  # fuchsia_tool_dir is used to specify the directory in the SDK to locate
-  # tools for the host cpu architecture. If the host_cpu is not recognized,
-  # then tool dir defaults to x64.
-  fuchsia_tool_dir = "${fuchsia_sdk}/tools/x64"
-  if (host_cpu == "arm64") {
-    fuchsia_tool_dir = "${fuchsia_sdk}/tools/arm64"
-  }
-}
-
-if (fuchsia_sdk_id == "") {
-  # Note: If we need to expose more than just the id in the future,
-  # we should consider exposing the entire json object for the metadata vs.
-  # adding a bunch of variables.
-  _meta = read_file(fuchsia_sdk_manifest_file, "json")
-  fuchsia_sdk_id = _meta.id
-}
+# Path to the fuchsia SDK. This is intended for use in other templates &
+# rules to reference the contents of the fuchsia SDK.
+fuchsia_sdk = "//third_party/fuchsia/sdk/$host_os"
 
 declare_args() {
   # Specify a readelf_exec path to use. If not specified, the host's system