[build] Clean up after soft transition

Clean up after fxrev.dev/637389

Change-Id: Ibd56cf4a1b81f3221f7f5994dcf96935954c701e
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/Vulkan-ValidationLayers/+/637390
Reviewed-by: Jay Zhuang <jayzhuang@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index c8e246c..d9c508f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -331,17 +331,7 @@
     defines = []
     ldflags = []
     if (is_fuchsia) {
-      # TODO(fxrev.dev/637122): remove the below after transition complete.
-      _old_config = [ "//build/config/fuchsia:thread_safety_annotations" ]
-      _new_config = [ "//build/config:thread_safety_annotations" ]
-      if (configs + _old_config - _old_config != configs) {
-        configs -= _old_config
-      }
-      if (configs + _new_config - _new_config != configs) {
-        configs -= _new_config
-      }
-      # TODO(fxrev.dev/637122): uncomment the below after transition complete.
-      #configs -= [ "//build/config:thread_safety_annotations" ]
+      configs -= [ "//build/config:thread_safety_annotations" ]
       ldflags += [ "-static-libstdc++" ]
     } else if (build_with_chromium) {
       configs -= [ "//build/config/compiler:chromium_code" ]