[SVLS-4918] use variables for node versions for future autoupdates

datadog_wrapper

@@ -159,10 +159,17 @@ setUpNodeEnv() {
     echo "Setting up Datadog tracing for Node"
     echo "Installing Node tracer"
 
+    if [ -z "${DD_NODE_TRACER_VERSION_4}" ]; then
+        DD_NODE_TRACER_VERSION_4=4.38.1
+    fi
+    if [ -z "${DD_NODE_TRACER_VERSION_5}" ]; then
+        DD_NODE_TRACER_VERSION_5=5.18.0
+    fi
+
     if [[ "$NODE_RUNTIME_VERSION" =~ ^v16.* ]]; then
-        yarn add "dd-trace@4.38.1" || return
+        yarn add "dd-trace@$DD_NODE_TRACER_VERSION_4" || return
     else
-        yarn add "dd-trace@5.18.0" || return
+        yarn add "dd-trace@$DD_NODE_TRACER_VERSION_5" || return
     fi
 
     ORIG_NODE_OPTIONS=$NODE_OPTIONS