bazel: Update TODO in bazelrc

Bug: 347317581
Change-Id: I92977af36f281da0047c0f81da7d55576a742c5b
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/216274
Reviewed-by: Dave Roth <davidroth@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Ted Pudlik <tpudlik@google.com>
diff --git a/.bazelrc b/.bazelrc
index 276b815..1acb63f 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -71,9 +71,8 @@
 
 # Silence compiler warnings from external repositories.
 #
-# This is supported by Bazel's default C++ toolchain, but not yet by
-# rules_cc_toolchain
-# (https://github.com/bazelembedded/rules_cc_toolchain/issues/46).
+# TODO: https://pwbug.dev/347317581 - This is supported by Bazel's default C++
+# toolchain, but not yet by Pigweed's own toolchains.
 build --features=external_include_paths
 
 # This feature can't be enabled until __unordtf2 and __letf2 are implemented by