Update RT_VER_NUM to 5.3.0 (RT-Thread#11039)

Rbb666 · web-flow · commit a036ddcb342f · 2025-12-12T10:34:53.000+08:00
diff --git a/src/Kconfig b/src/Kconfig
@@ -434,7 +434,7 @@ endif
 
 config RT_VER_NUM
     hex
-    default 0x50201
+    default 0x50300
     help
         RT-Thread version number
 
