ci: use larger github actions runner (#34833)

Use 32 core instance for the PR build. Also updates actions to the latest versions.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: mrgrain

.github/workflows/pr-build.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: aws-cdk_ubuntu-latest_16-core
+    runs-on: aws-cdk_ubuntu-latest_32-core
 
     env:
       PR_BUILD: true
@@ -18,7 +18,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Node.js
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: "18"
           cache: "yarn"
@@ -31,7 +31,7 @@ jobs:
       #   run: /root/ecr-proxy/start.sh
 
       - name: Cache build artifacts
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             ~/.s3buildcache