Update to Node.js v20

[Piedone]

Description

Updated the Node.js version from 16 to 20.

Motivation and Context

Node 16 is deprecated, see https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/. You get warnings when running an action using Node 16.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Enhancement (changes that improvement of current feature or performance)
• Refactoring (changes that neither fixes a bug nor adds a feature)
• Test Case (changes that add missing tests or correct existing tests)
• Code style optimization (changes that do not affect the meaning of the code)
• Docs (changes that only update documentation)
• Chore (changes that don't modify src or test files)

Self Check before Merge

• My code follows the code style of this project.
• [] My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Piedone]

I just see #12 is for this too.