[roll third_party/pigweed] pw_blob_store: Don't assert on BlobReader seeks or reads

Return FAILED_PRECONDITION if seeking or reading from a closed
BlobStore::BlobReader.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/77823

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 51ff972f0cbe8f5..3ce31ccbd3cad5b
Roller-URL: https://ci.chromium.org/b/8825375280699271937
Cq-Cl-Tag: roller-builder:pigweed-sample-project-roller
Cq-Cl-Tag: roller-bid:8825375280699271937
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I28c55d3c9ab1bd3a9d6771eb54be134542ea7726
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/77901
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 51ff972..3ce31cc 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 51ff972f0cbe8f5c414a666ea92af38e80db8cc7
+Subproject commit 3ce31ccbd3cad5b72fdf103c7dcd5969487b14ae