Brake 4338 out for a specific config

Author: mkardous-silabs

.github/silabs-builds.json

@@ -1,8 +1,13 @@
 {
     "lighting-app": [
         {
-            "boards": ["BRD4186C", "BRD4187C", "BRD4338A"],
+            "boards": ["BRD4186C", "BRD4187C"],
             "arguments": ["--docker"]
+        },
+        {
+            "boards": ["BRD4338A"],
+            "arguments": ["--docker", "use_rps_extension=false"]
         }
+
     ]
 }