Fix CI: remove py3.8/3.9 from test workflow (requires >=3.10)

[mewincaka]

GitHub Actions fix: CI was failing on Python 3.9 because epydem now requires Python >= 3.10 (pyproject.toml).

Changes

• Consolidate CI by removing redundant .github/workflows/test.yml (keep ci.yml as the single CI).
• Ensure CI only tests supported Python versions (>=3.10).
• Install via pip install -e '.[dev]' (single source of truth).
• Add a quick import smoke test to CI.

Why this implementation

• Running CI on unsupported Python versions creates noisy failures and slows iteration.
• Keeping workflows consistent reduces maintenance and confusion.

Multi-role debate (differences, not consensus)

Role A — pragmatic developer

• 👍 Likes: CI goes green and matches supported versions; simpler workflow.
• ⚠️ Concern: removes older-Python signal; but we explicitly don’t support <3.10.

Role B — architecture

• 👍 Likes: single tooling stack (ruff) and consistent install path.
• ⚠️ Concern: having both ci.yml and test.yml is redundant; consider consolidating later.

Role C — developer user (DX)

• 👍 Likes: less CI noise; clearer support policy.
• ⚠️ Concern: if users want older Python, they’ll need a documented support decision.

Points of divergence to revisit later

1. Consolidate workflows (keep one CI file).
2. Add python-version: 3.13 when ready.

[kengggg]

@notskynet-bot thank you. I don't care about older python < 3.10 so there's no need to make our lib backward compatible.

I think one improvement should be done is to consolidate ci.yml and test.yml. I'm not sure why we have redundant actions, but keeping only one true CI and Test is better.

[mewincaka]

Thanks — agreed. I consolidated the workflows so we only have one CI.

What changed in this PR:

• Removed the redundant .github/workflows/test.yml.
• Kept .github/workflows/ci.yml as the single source of truth.
• CI still tests Python 3.10–3.12 (matches requires-python >= 3.10).
• Added a quick import smoke test to CI.

Commit: 1f20664