Update pthreadpool revision

- Pull a fix for inline assembly on old binutils
- Use more efficient C11 atomics-based implementation
- Disable legacy API to avoid deprecated warnings

PiperOrigin-RevId: 277304317
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7c5b58f..4f392ab 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -656,6 +656,7 @@
 IF(NOT TARGET pthreadpool)
   SET(PTHREADPOOL_BUILD_TESTS OFF CACHE BOOL "")
   SET(PTHREADPOOL_BUILD_BENCHMARKS OFF CACHE BOOL "")
+  SET(PTHREADPOOL_ALLOW_DEPRECATED_API OFF CACHE BOOL "")
   ADD_SUBDIRECTORY(
     "${PTHREADPOOL_SOURCE_DIR}"
     "${CMAKE_BINARY_DIR}/pthreadpool")