[roll third_party/pigweed] pw_string: Match std::string semantics for literal / array overloads

Previously, the constructor, assign, and append overloads for string
literals or arrays used the length of the array as the length of the
string, and dropped the final character only if it was a null
terminator.

This avoided some strlen() calls and made assigning to an InlineString
more like working with an ""sv string literal. However, since the
character array is not guaranteed to be null terminated, this approach
had some drawbacks:

- A string of length N could not be assigned to an InlineString<N>, to
  account for non-terminated character arrays.
- The capacity template argument would be deduced to a value one larger
  than the length of the string.
- Behavior was inconsistent with std::string, since nulls could be
  included in assignments.

This commit updates pw::InlineString's string literal or array overloads
to use the same semantics as std::string. Unlike std::string,
pw::InlineString checks the array size to prevent out-of-bounds reads.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/111711

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 3da49f09465804b..71a3266aa316744
Roller-URL: https://ci.chromium.org/b/8801821297538188049
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iad0b9b9903653008f3cfe957a832b76fb25ac6db
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/112353
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 3da49f0..71a3266 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 3da49f09465804b65240884e10c76636086fd3bc
+Subproject commit 71a3266aa316744d980bf2a4eb3d4129923ce99f