Remove printable charlists from bird-count (lists)

[angelikatyborska]

Bird count is one of the first learning exercises, and it's about lists. Sooner or later Elixir learners will hit the confusing behavior of lists of integers being charlists, and thus printable list of integers being always printed as charlists. However, I think we can postpone that happening to a later exercise, ideally the one about charlists 🙂

This issue was brought to my attention by this forum post: https://forum.exercism.org/t/bird-count-test-case-appears-to-use-sigils/8922

[github-actions]

Thank you for contributing to exercism/elixir 💜 🎉. This is an automated PR comment 🤖 for the maintainers of this repository that helps with the PR review process. You can safely ignore it and wait for a maintainer to review your changes.

Based on the files changed in this PR, it would be good to pay attention to the following details when reviewing the PR:

• General steps

  • 🏆 Does this PR need to receive a label with a reputation modifier (x:size/{tiny,small,medium,large,massive})? (A medium reputation amount is awarded by default, see docs)

• Any exercise changed

  • 👤 Does the author of the PR need to be added as an author or contributor in <exercise>/.meta/config.json (see docs)?
  • 🔬 Do the analyzer and the analyzer comments exist for this exercise? Do they need to be changed?
  • 📜 Does the design file (<exercise>/.meta/design.md) need to be updated to document new implementation decisions?

• Concept exercise changed

  • 🌲 Do prerequisites and practices in config.json need to be updated?
  • 📖 Does the concept introduction provide all necessary information to solve this exercise?

• Concept exercise tests changed

  • ⚪️ Are all tests un-skipped?
  • 🔢 Are all tests annotated with @tag task_id?
  • 🐈 Can all tests be understood by reading the test's block only (e.g. no module attributes, no setup functions)?

---

Automated comment created by PR Commenter 🤖.

[jiegillet]

Sounds good to me