Add a script to update the schemastore (#4574)
* Add a script to update the schemastore
Hacked this together, it clones astral-sh/schemastore, updated the schema and pushes the changes
to a new branch tagged with the ruff git hash. You can see the URL to create the PR
to schemastore in the CLI. The script is separated into three blocks so you can rerun
the schema generation in the middle before committing.
* Use tempdir for schemastore
* Add comments
