feat: support node20 runtime (#1988)

* feat: support node20

* fix

* more fixes

* maybe final fixes?

* format

pkg/runner/testdata/actions/node20/node_modules/universal-user-agent/dist-src/index.js

@@ -0,0 +1,9 @@
+export function getUserAgent() {
+    if (typeof navigator === "object" && "userAgent" in navigator) {
+        return navigator.userAgent;
+    }
+    if (typeof process === "object" && "version" in process) {
+        return `Node.js/${process.version.substr(1)} (${process.platform}; ${process.arch})`;
+    }
+    return "<environment undetectable>";
+}