ERROR at //build/config/BUILDCONFIG.gn:561:19: Unable to load "/chromium-135.0.7049.41/buildtools/third_party/libc++/BUILD.gn".
        deps += [ "//buildtools/third_party/libc++:std" ]
                  ^------------------------------------


Since we're not building clang, we don't need this.

--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -532,7 +532,10 @@ set_defaults("rust_proc_macro") {
   configs = default_rust_proc_macro_configs
 }
 
-DEFAULT_MODULE_DEPS = [
+DEFAULT_MODULE_DEPS = []
+junk = []
+not_needed(["junk"])
+junk = [
   "//buildtools/third_party/libc++:_Builtin_float",
   "//buildtools/third_party/libc++:_Builtin_intrinsics",
   "//buildtools/third_party/libc++:_Builtin_inttypes",