roll: third_party/pigweed: pw_toolchain: Expose a symlink to clangd

Running,

    bazelisk build //pw_toolchain/host_clang:copy_clangd

creates a symlink to clangd at bazel-bin/pw_toolchain/host_clang/clangd.

Original-Bug: 355655415
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/226262
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 88f05c77b478b16..7bbbec8a98bcf12
Roller-URL: https://ci.chromium.org/b/8741052105403416241
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I1e4c206869721755389b29a21e0267dbd479e3ae
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/226263
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 88f05c7..7bbbec8 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 88f05c77b478b1630c935e13f4bc7bcceaad8c22
+Subproject commit 7bbbec8a98bcf129872da475b0a46a5a96f09916