gh-150644: Tag Apple system log messages as public. (GH-150645)

macOS 26 changed the default visibility of "dynamic" system messages. This
changes the logging strategy to tag all messages as "public" so they are
visible in the system log without special configuration.
(cherry picked from commit 71fc4c6)

Co-authored-by: Russell Keith-Magee <russell@keith-magee.com>

Author: freakboy3742

Misc/NEWS.d/next/macOS/2026-05-31-10-40-00.gh-issue-150644.zLWyjj.rst

@@ -0,0 +1,3 @@
+When system logging is enabled (with ``config.use_system_logger``, messages
+are now tagged as public. This allows the macOS 26 system logger to view
+messages without special configuration.

Python/pylifecycle.c

@@ -3324,7 +3324,9 @@ apple_log_write_impl(PyObject *self, PyObject *args)
 
     // Pass the user-provided text through explicit %s formatting
     // to avoid % literals being interpreted as a formatting directive.
-    os_log_with_type(OS_LOG_DEFAULT, logtype, "%s", text);
+    // Using {public} ensures "dynamic" string messages are visible
+    // in the log without special configuration.
+    os_log_with_type(OS_LOG_DEFAULT, logtype, "%{public}s", text);
     Py_RETURN_NONE;
 }