Remove the ignore rule for editor on workspaces

MR: Remove ignore rule for editor field on workspaces (!167825 - merged)

Description

As a follow up to this issue: Drop editor field in workspaces table as it is ... (#486301 - closed) where we added the ignore rule and dropped the editor field.

We want to remove the ignore rule for the editor field on the Workspace model

This rule was added as part of release M (%17.5), following the process Dropping columns

And in release M+2 (%17.7) we should remove this rule.

Acceptance Criteria

• Remove ignore rule for editor field in the RemoteDevelopment::Workspace model.
• Remove IgnorableColumns if there aren't any other ignore rules defined in the model.