Update node version to 24.x in Docker workflow

This change updates the Node.js version used in the
Docker workflow from 20.x to 24.x.

Signed-off-by: Jose Javier Merchante <jjmerchante@bitergia.com>

Author: jjmerchante

.github/workflows/docker-image.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [20.x]
+        node-version: [24.x]
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Setup Node ${{ matrix.node-version }}