Bump project classification from Pre-Alpha to Alpha

[tpvasconcelos]

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📚 Documentation preview 📚: https://ridgeplot--336.org.readthedocs.build/en/336/

[Copilot]

Pull Request Overview

This PR updates the project's development status classification from "Pre-Alpha" to "Alpha" in the package metadata, indicating the project has reached a more mature development stage.

• Updates the PyPI classifier in pyproject.toml from "Development Status :: 2 - Pre-Alpha" to "Development Status :: 3 - Alpha"
• Documents this classification change in the changelog

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pyproject.toml	Updates the development status classifier from Pre-Alpha to Alpha
docs/reference/changelog.md	Adds changelog entry documenting the classification bump

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (5b8342f) to head (e277756).
⚠️ Report is 104 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #336   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           18        18           
  Lines          655       655           
  Branches        83        83           
=========================================
  Hits           655       655           

Flag	Coverage Δ
combined-src	99.84% <ø> (ø)

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