Follow-up from #393900: Step 3

What

Follow-up from Remove the ignore rule for chat_names. integrat... (!126186 - merged), and related to Remove the ignore rule for chat_names. integrat... (#393900 - closed) step 2, and step 3.

We should remove the IgnoreColumn from ChatNames model.

Proposal

1. Remove the following code from app/models/chat_name.rb

include IgnorableColumns
ignore_column :integration_id, remove_with: '16.0', remove_after: '2023-04-22'

1. Update the following specs:

• spec/db/schema_spec.rb