fix: update repository for Probot v13

Author: wolfy1339

.github/workflows/test.yml

@@ -15,6 +15,6 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           cache: npm
-          node-version: 16
+          node-version: 20
       - run: npm ci
       - run: npm test

app.js

@@ -2,7 +2,7 @@
  * @param {import('probot').Probot} app
  */
 module.exports = (app) => {
-  app.log("Yay! The app was loaded!");
+  app.log.info("Yay! The app was loaded!");
 
   app.on("issues.opened", async (context) => {
     return context.octokit.issues.createComment(