Make CI fail if have a difference

[szepeviktor]

Nothing should change.

[mlocati]

In my mind, when a new Unicode version is published, I'd adopt this process:

• Update the value DEFAULT_VERSION in bin/unipoints
• create a pull request
• when the pull request gets merged, the GitHub Action
  • will re-create the enums
  • will see that there are differences
  • will push back to main the changes

So, developers won't have to manually run bin/unipoints build: everything will be automatic.

PS: that's what I meant with #4

[mlocati]

@szepeviktor Here's what I meant: #21