Relax jsonschema dependency

[ostefano]

Any hard reason why the jsonschema dependency is so restrictive: jsonschema[format-nongpl]>=4.6.0,<4.18.0?

As things stand it is not possible to install cti-stix-validator together with pymisp, with cti-stix-validator having the most restrictive selection.

[ejratl]

As I recall, there was a breaking change in jsonschema that requires updates to the validator code to work with 4.18.0 and later. Since we don't yet have a pull request for the new way of doing things, upgrading to the latest version of jsonschema is not possible.
The release notes for jsonschema 4.18.0 describe the change that is needed: https://github.com/python-jsonschema/jsonschema/releases/tag/v4.18.0
"jsonschema.RefResolver is now deprecated in favor of the new referencing library."

[ejratl]

This issue is a duplicate of #216

[ostefano]

Here the PR fixing this issue: #228

[ostefano]

@clenk @rpiazza could you review the linked PR? Thanks!

[ostefano]

This has been fixed #228