[roll third_party/pigweed] pw_allocator: Remove total_bytes metric

Previously, `pw::allocator::Metrics` had a field for `total_bytes`. This
is not particularly interesting, as it is a value that isn't expected
to change. It also is a bit difficult, as a `TrackingAllocator` has no
way to interrogate an `Allocator` it is handed for its implementation-
specific capacity. As a result, this CL removes the field.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/193251

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: a5038affded6fea..e8c65f4cc0c1568
Roller-URL: https://ci.chromium.org/b/8755351799255185937
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I42c069412d98822d31a84713e0225fb7083dc11b
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/193596
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index a5038af..e8c65f4 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit a5038affded6feab2522a7dcc781c21c4f16cc1e
+Subproject commit e8c65f4cc0c1568b45fa42439f8bddb50ca327c9