Only include npm version if npm exists

dist/index.js

@@ -15228,8 +15228,11 @@ function run() {
             const nodeVersion = child_process_1.default.execSync(`${nodePath} --version`);
             console.log(`Node Version: ${nodeVersion}`);
             const npmPath = yield io.which('npm');
+            // Older versions of Node don't include npm
+            if (npmPath) {
                 const npmVersion = child_process_1.default.execSync(`${npmPath} --version`);
                 console.log(`npm Version: ${npmVersion}`);
+            }
             const registryUrl = core.getInput('registry-url');
             const alwaysAuth = core.getInput('always-auth');
             if (registryUrl) {

src/setup-node.ts

@@ -25,8 +25,11 @@ async function run() {
     console.log(`Node Version: ${nodeVersion}`);
 
     const npmPath = await io.which('npm');
+    // Older versions of Node don't include npm
+    if (npmPath) {
       const npmVersion = cp.execSync(`${npmPath} --version`);
       console.log(`npm Version: ${npmVersion}`);
+    }
 
     const registryUrl: string = core.getInput('registry-url');
     const alwaysAuth: string = core.getInput('always-auth');