Use correct version of node

Author: DavyLandman

.github/workflows/pr-builder.yml

@@ -20,6 +20,11 @@ jobs:
         with:
           name: sources
 
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: yarn
+
       # Do a dummy build to see if there are errors
       - name: Install dependencies
         run: yarn install --frozen-lockfile