roll: third_party/pigweed bazel: Set explicit mnemonic for Starlark actions

In a downstream repo, it will soon be required for all actions to
have a mnemonic set for starlark actions (ref cl/872469290).

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/377292
Original-Revision: bbc2523697fd4fb0fcc6b0b47a6e10c2ccb60d88

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 7ba958a0c2c164..bbc2523697fd4f
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8688946149826308705
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Id4f612c786ddb6d2f489abea5770647d194d97c5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/379095

third_party/pigweed

diff --git a/third_party/pigweed b/third_party/pigweed
index 7ba958a..bbc2523 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 7ba958a0c2c1647675af1149f269770e5dac3900
+Subproject commit bbc2523697fd4fb0fcc6b0b47a6e10c2ccb60d88