fix(ui-checkbox): announce the toggle variant as a toggle button

[ToMESSKa]

INSTUI-5023

ISSUE:

• Checkbox toggle variant looks and behaves like a toggle button but announced as checkbox so role and state (checkbox/checked) don't match the presented control (toggle). A suggested fix is adding role=”button” and aria-pressed=”false/true” to the <input>, see https://instructure.atlassian.net/browse/LRN-11564

TEST PLAN:

• check the Checkbox toggle variant with VoiceOver and NVDA, it should be announced as a "toggle button"

[github-actions]

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[github-actions]

Visual regression report

⚠️ Changes detected.

Status	Count
Unchanged	0
Changed	1
New	96
Removed	32

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Diff images (33)

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_{Baselines come from the visual-baselines branch. They refresh on every merge to master.}