Upgrade the eslint-annotation and stylelint-annotation actions to use Node.js v20

[eason9487]

Changes proposed in this Pull Request:

Part of #108

This PR upgrades the eslint-annotation and stylelint-annotation actions to use Node.js v20

Detailed test instructions:

1. View a previous workflow run used v1 eslint-annotation and stylelint-annotation actions
   • https://github.com/woocommerce/automatewoo-birthdays/actions/runs/8699515674
   • There are warnings of using Node.js 16
     
2. View a test workflow run used updated eslint-annotation and stylelint-annotation actions
   • https://github.com/woocommerce/automatewoo-birthdays/actions/runs/8815885945?pr=134
   • This run failed on purpose to test if it can report JS and CSS linting errors
   • There's no more warning of using Node.js 16
     
3. View the test PR
   • woocommerce/automatewoo-birthdays/pull/134
   • The annotations are shown
     
     
     

[eason9487]

I will be skipping the code review process as it can be optional for a devs-facing only change.