[roll third_party/pigweed] pw_cli: Fix commit fallback handling for GitRepo.list_files()

The wrong error type was being caught in the handling of fallback logic
for GitRepo.list_files(). This ensures the correct error is caught, and
adds a test to verify.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/203790

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 6913460a9bd1bd6..ffd7f02f75eec34
Roller-URL: https://ci.chromium.org/b/8750479511439119665
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Icdd213813f0b1488d11ea190b374a8ef2fe69a2c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/203870
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 6913460..ffd7f02 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 6913460a9bd1bd66b653a02759dcd8a334807fca
+Subproject commit ffd7f02f75eec34f060dd93803b7441668ef7e1f