roll: third_party/pigweed pw_containers: Add pw::DynamicMap

This change introduces `pw::DynamicMap`, a sorted map container that uses a caller-provided `pw::Allocator` to dynamically allocate nodes. It is implemented on top of `pw::IntrusiveMap`.

Key features include:
- Dynamic node allocation via `pw::Allocator`.
- API similar to `std::map`.
- `try_` methods for operations that can fail due to allocation failure.
- Move semantics for efficient transfer of ownership.

Original-Bug: 471527898
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/359892
Original-Revision: 4dc4a90fc765e6b26013f0efd657ca4b24bbf330

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 21779c05546405..4dc4a90fc765e6
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8688331649701969057
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I24c0e7ee6546b637b9f91de7fff08a11b6a30270
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/381413
diff --git a/third_party/pigweed b/third_party/pigweed
index 21779c0..4dc4a90 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 21779c05546405c1d31c522b8b532224a99af030
+Subproject commit 4dc4a90fc765e6b26013f0efd657ca4b24bbf330