Remove hacks to metro BUCK for handling macos_legacy

Summary: Backs out all of the changes introduced in D68246115 as they are no longer needed.

Reviewed By: IanChilds

Differential Revision: D74860891

fbshipit-source-id: aa528e70c7c3674b69a02e2cb7ff8d1927c26852

Author: rozele

prelude/js/js.bzl

@@ -21,8 +21,6 @@ def _select_platform():
             "config//os/constraints:windows": "windows",
         }),
         "config//react-native:macos": "macos",
-        # TODO(T210407097): Remove after deleting //third-party/microsoft-fork-of-react-native
-        "fbsource//tools/build_defs/js/config:macos_legacy": "macos_legacy",
         "fbsource//tools/build_defs/js/constraints/metro_js_platform_override:android": "android",
         "fbsource//tools/build_defs/js/constraints/metro_js_platform_override:ios": "ios",
         "fbsource//tools/build_defs/js/constraints/metro_js_platform_override:macos": "macos",

prelude/js/js_utils.bzl

@@ -58,10 +58,10 @@ ASSET_EXTENSIONS = [
 ]
 
 # Matches the default value for resolver.platforms in metro-config
-ASSET_PLATFORMS = ["ios", "android", "windows", "macos", "macos_legacy", "web"]
+ASSET_PLATFORMS = ["ios", "android", "windows", "macos", "web"]
 
 def get_apple_resource_providers_for_js_bundle(ctx: AnalysisContext, js_bundle_info: JsBundleInfo, platform: str, skip_resources: bool) -> list[ResourceGraphInfo]:
-    if platform != "ios" and platform != "macos" and platform != "macos_legacy":
+    if platform != "ios" and platform != "macos":
         return []
 
     # `skip_resources` controls whether the JS resources should be skipped, not whether
@@ -126,7 +126,7 @@ def get_bundle_name(ctx: AnalysisContext, default_bundle_name: str) -> str:
     flavors = bundle_name_for_flavor_map.keys()
     for flavor in flavors:
         expect(
-            flavor == "android" or flavor == "ios" or flavor == "macos" or flavor == "macos_legacy" or flavor == "windows" or flavor == "vr",
+            flavor == "android" or flavor == "ios" or flavor == "macos" or flavor == "windows" or flavor == "vr",
             "Currently only support picking bundle name by platform!",
         )