Update dependency node to v24

Author: renovate[bot]

.github/workflows/diffy.yml

@@ -38,7 +38,7 @@ jobs:
         #      if: steps.base-diff.outputs.cache-hit != 'true'
         uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version: 24
       - name: Install diff2html
         #      if: steps.base-diff.outputs.cache-hit != 'true'
         run: npm -g install diff2html-cli diff2html