[roll third_party/pigweed] pw_thread: improve error if join() is called when not enabled

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/55840

third_party/pigweed Rolled-Commits: 9f3708c3a1770f2..278ba0ff46b7844
Roller-URL: https://ci.chromium.org/b/8839888742224436449
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8839888742224436449
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I5a982dadf6e652d36c48f6f104930690e4d007a5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/55943
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 9f3708c..278ba0f 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 9f3708c3a1770f29b9c60aa921912258203926b7
+Subproject commit 278ba0ff46b784426125f9611f3202d9dd69bef6