S. Riette 16 Nov 2023: change testprogs ref to enable automatic build of the reference

Due to the switch between filepp/mnh_expand and pyft_tool.py,
old commits cannot be compiled with the tools provided by recent commits

src/testprogs/testprogs_version.json

 {
 "testing": {
-            "ice_adjust":"41c6be7",
-            "rain_ice":"41c6be7",
-            "rain_ice_old":"41c6be7",
-            "turb":"41c6be7",
-            "shallow":"41c6be7"
+            "ice_adjust":"19ee594",
+            "rain_ice":"19ee594",
+            "rain_ice_old":"19ee594",
+            "turb":"19ee594",
+            "shallow":"19ee594"
            }
 }