roll: third_party/pigweed pw_libcxx: Make libcxx_hooks an OBJECT library

Change the library type of pw_libcxx.libcxx_hooks from STATIC to OBJECT.
This guarantees that overridden weak standard library symbols (such as
std::__libcpp_verbose_abort) are always pulled in during link time,
rather than being bypassed in favor of weak definitions inside prebuilt
archives like libc++.a.

Also add missing dependencies on pw_assert.check and pw_string required
by verbose_abort.cc.

Original-Bug: 532515375
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/433793
Original-Revision: 23f2c4150ac5f16c048db23bc7217ff8faba15ae

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 204f542d778643..23f2c4150ac5f1
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8676786812797422065
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ie09adaea86629493e7c3eae45ceb78c21080facd
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/434132
diff --git a/third_party/pigweed b/third_party/pigweed
index 204f542..23f2c41 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 204f542d77864384aa10aab4f06fe3e07b70b95c
+Subproject commit 23f2c4150ac5f16c048db23bc7217ff8faba15ae