feat: support node20 runtime (#1988)

* feat: support node20

* fix

* more fixes

* maybe final fixes?

* format

pkg/runner/testdata/actions/node20/index.js

@@ -0,0 +1,15 @@
+const core = require('@actions/core');
+const github = require('@actions/github');
+
+try {
+  // `who-to-greet` input defined in action metadata file
+  const nameToGreet = core.getInput('who-to-greet');
+  console.log(`Hello ${nameToGreet}!`);
+  const time = (new Date()).toTimeString();
+  core.setOutput("time", time);
+  // Get the JSON webhook payload for the event that triggered the workflow
+  const payload = JSON.stringify(github.context.payload, undefined, 2)
+  console.log(`The event payload: ${payload}`);
+} catch (error) {
+  core.setFailed(error.message);
+}