Add IE and PL to merino curated recs

[adudenamedruby]

Pull Request checklist

• Breaking changes: This PR follows our breaking change policy
  • This PR follows the breaking change policy:
    • This PR has no breaking API changes, or
    • There are corresponding PRs for our consumer applications that resolve the breaking changes and have been approved
• Quality: This PR builds and tests run cleanly
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• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry in CHANGELOG.md or an explanation of why it does not need one
  • Any breaking changes to Swift or Kotlin binding APIs are noted explicitly
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  • Any new dependencies are accompanied by a summary of the due diligence applied in selecting them.

This PR is simply adding additional locales to Merino, and that's not something that needs to be covered by the changelog.

The pull request has been modified, dismissing previous reviews.