chore: run yarn-upgrade workflow on latest available node version (#26437)

This should just use the latest available version. We can do proper version tests on the PR that it creates.

Fixes failing action: https://github.com/aws/aws-cdk/actions/runs/5599894597/jobs/10242602721

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Author: mrgrain

.github/workflows/yarn-upgrade.yml

@@ -20,7 +20,7 @@ jobs:
       - name: Set up Node
         uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: "*"
         env:
           NODE_OPTIONS: "--max-old-space-size=8196 --experimental-worker ${NODE_OPTIONS:-}"