common: Intentionally leak logger instance to fix hanging on Windows (#22273)

* Changed to leak logger singleton to prevent hanging on Windows

* Fix comment

* Stopped using static vector

Using std::vector will cause g_col to be released before the logger thread exits, causing the logger thread to touch freed memory causing a crash

* Change so all logs are output before exit

* Added debug logging

* added more logging

* Added logging

* Explicitly free logger to avoid hanging on Win

* Reverted to leak logger instance again

* Removed debug log and fixed comment

* Fixed comment

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

tests/test-log.cpp

@@ -35,5 +35,9 @@ int main() {
         threads[i].join();
     }
 
+    common_log_flush(common_log_main());
+    // We explicitly free the logger singleton to avoid hanging on Windows
+    // related to timing issues of thread startup and DLL teardown
+    common_log_free(common_log_main());
     return 0;
 }