refactor: Drop col column 'package_name_pattern_ilike_query' Part 1

This MR includes:
- Ignoring the column 'package_name_pattern_ilike_query'
  in table 'packages_protection_rule'
- Enable null values for colum 'package_name_pattern_ilike_query'
- Changes for the 2nd part for dropping a column based
  on the GitLab guide, see
    https://docs.gitlab.com/ee/development/database/avoiding_downtime_in_migrations.html#dropping-columns
- Changes relevant for protected packages

Changelog: removed