fix workflow-edits workflow

[edublancas]

the workflow-edits fails the CI if a given PR modifies the .github/workflows directory. However, it has an issue.

It'll also fail if the change originated from the master/main branch - which shouldn't. The problem is in the git diff command, we can fix by using the ... operator (as explained here)

we also need to update jupysql's copy: https://github.com/ploomber/jupysql/blob/master/.github/workflows/workflow-edits.yml