docs: add 1.3.x to SECURITY.md

Author: benja2998

SECURITY.md

@@ -6,6 +6,7 @@ This is the status of the current versions of this software.
 
 | Version | End Of Life
 | ------- |  -------------- 
+| 1.3.x   | March 4, 2026
 | 1.2.x   | March 2, 2026
 | 1.1.x   | August 31, 2025
 | 1.0.x   | August 30, 2025