[Redmine BT] Locked or closed versions should not be displayed in Version CUFs

Affected version : bugtracker.redmine-12.0.2.RELEASE

Steps to reproduce

• Have a Redmine project with a custom field of the "version" type.
• Add the created custom version field as a "tracker" on the Redmine project.
• Create 2 versions, close one of them.
• On a SquashTM project, add a Redmine bugtracker server pointing to the Redmine project.
• Execute a test case and open the anomaly report form.
• Click on the custom version field.

Observed behaviour

The issue report form allows the user to pick a locked or closed version in the custom field of the "version" type.

Expected result

Closed or locked versions should not be selectable options in version CUFs, similarly to how the native version field behaves.