roll: third_party/pigweed bazel: Roll rules_rust to 0.70.0

Original-Bug: 392707726

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/406813
Original-Revision: e8ff0508b8543768228993652bd75c3b44b2158d

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: a20565cb512ae4..e8ff0508b85437
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8682597798587116721
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I49cf9a3f33047118fce80844e8111adce8cd4c6c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/406973
diff --git a/third_party/pigweed b/third_party/pigweed
index a20565c..e8ff050 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit a20565cb512ae4eebdea1b96928c274d4b9deab5
+Subproject commit e8ff0508b8543768228993652bd75c3b44b2158d