adding agent knob AGENT_RESTRICT_EOL_NODE_VERSIONS

Author: rishabhmalikMS

src/Agent.Sdk/Knob/AgentKnobs.cs

@@ -575,6 +575,13 @@ public class AgentKnobs
             new EnvironmentKnobSource("AGENT_RESTRICT_EOL_NODE_VERSIONS"),
             new BuiltInDefaultKnobSource("false"));
 
+        public static readonly Knob EnableEOLNodeVersionPolicy = new Knob(
+            nameof(EnableEOLNodeVersionPolicy),
+            "When enabled, automatically upgrades tasks using end-of-life Node.js versions (6, 10, 16) to supported versions (Node 20.1 or Node 24). Throws error if no supported versions are available on the agent.",
+            new PipelineFeatureSource("AGENT_RESTRICT_EOL_NODE_VERSIONS"),
+            new EnvironmentKnobSource("AGENT_RESTRICT_EOL_NODE_VERSIONS"),
+            new BuiltInDefaultKnobSource("false"));
+
         public static readonly Knob DisableTeePluginRemoval = new Knob(
             nameof(DisableTeePluginRemoval),
             "Disables removing TEE plugin after using it during checkout.",