roll: pigweed pw_protobuf_compiler: Fix unused variable

use_legacy_oneof_interfaces is an optional variable and might not be
used. This triggers the GN "unused" error.

Original-Bug: 382416987
Test: Build pass
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/278332
Original-Revision: 2861b6ad5f94c2c8b4b393761d93c568eef9547e

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 3003d35d53be38..2861b6ad5f94c2
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8719459497948746769
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I8782698396f3b61f929342c4c9486b74658411be
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/showcase/sense/+/278366
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/MODULE.bazel b/MODULE.bazel
index f4c11f8..00409a8 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -42,8 +42,8 @@
     module_name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2025-03-25.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8719470356310230465.
-    commit = "3003d35d53be38d41a67907b59591edc8aeaf73d",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8719459497948746769.
+    commit = "2861b6ad5f94c2c8b4b393761d93c568eef9547e",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed",
 )