Issue #19760: Silence sysconfig's 'SO' key deprecation warnings in tests.
Change stacklevel in warnings.warn() for 'SO' key to 2.
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index ffa772e..dbf7767 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -585,7 +585,7 @@
     """
     if name == 'SO':
         import warnings
-        warnings.warn('SO is deprecated, use EXT_SUFFIX', DeprecationWarning)
+        warnings.warn('SO is deprecated, use EXT_SUFFIX', DeprecationWarning, 2)
     return get_config_vars().get(name)