[libc] Fix integration test header dependency.

GitOrigin-RevId: 0dcdc1c863ebfdefaab98459fe050bd055a54367
diff --git a/test/src/CMakeLists.txt b/test/src/CMakeLists.txt
index 3dc9394..432b619 100644
--- a/test/src/CMakeLists.txt
+++ b/test/src/CMakeLists.txt
@@ -30,7 +30,7 @@
           ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td
 
   DEPENDS ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td
-          libc-prototype-testgen ${PUBLIC_HEADERS}
+          libc-prototype-testgen ${TARGET_PUBLIC_HEADERS}
           llvmlibc llvmlibm
 )