fix: add aria-expanded on ms-drop element, fixes #178

[ghiscoding]

• fixes Accessibility attributes #178

[github-actions]

🎭 Playwright Summary - Success 🎉

Playwright Report

multiple-select-vanilla-root@0.0.0 test:e2e /home/runner/work/multiple-select-vanilla/multiple-select-vanilla
playwright test --config playwright/playwright.config.ts

Running 69 tests using 2 workers
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69 passed (56.0s)