Threatening downstream maintainers on stdout may be fun, but it breaks `gn desc` which we call in %install

--- src/build/config/c++/c++.gni	2025-04-16 14:36:21.927410223 +0200
+++ src/build/config/c++/c++.gni	2025-04-19 00:11:43.759874434 +0200
@@ -110,16 +110,3 @@ assert(!(is_ios && libcxx_is_shared),
 
 # Chromium will require using its libc++ library implementation. Warn if the
 # current configuration is not using it.
-if ((!use_custom_libcxx || !use_custom_libcxx_for_host) &&
-    # Standalone use of //build outside of Chromium can disable libc++.
-    build_with_chromium &&
-    # Try to avoid spamming the console lots. It's not actually
-    # toolchain-specific.
-    current_toolchain == default_toolchain) {
-  print("*********************************************************************")
-  print("WARNING: Support for linking against a C++ standard library other ")
-  print("  than the one in-tree (buildtools/third_party/libc++) is deprecated")
-  print("  and support for this will end. We plan to remove this option in ")
-  print("  M138.")
-  print("*********************************************************************")
-}