Issue #9425: Create PyErr_WarnFormat() function

Similar to PyErr_WarnEx() but use PyUnicode_FromFormatV() to format the warning
message.

Strip also some trailing spaces.
diff --git a/Misc/NEWS b/Misc/NEWS
index 4f6d3b3..dc3191f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #9425: Create PyErr_WarnFormat() function, similar to PyErr_WarnEx()
+  but use PyUnicode_FromFormatV() to format the warning message.
+
 - Issue #8530: Prevent stringlib fastsearch from reading beyond the front
   of an array.
 
@@ -85,7 +88,7 @@
   Thread-local objects involved in reference cycles will be deallocated
   timely by the cyclic GC, even if the underlying thread is still running.
 
-- Issue #9452: Add read_file, read_string, and read_dict to the configparser 
+- Issue #9452: Add read_file, read_string, and read_dict to the configparser
   API; new source attribute to exceptions.
 
 - Issue #6231: Fix xml.etree.ElementInclude to include the tail of the