fix(button): reflect loading state in aria-disabled

[zigzagdev]

Description 📄

[Enter the description of your changes]

The disabled HTML attribute on Button already accounted for isLoading (disabled={disabled || isLoading}), but aria-disabled only reflected the disabled prop.
Screen reader users could be told a loading button was still interactive.
Updated aria-disabled to also reflect isLoading, falling back to undefined when neither disabled nor isLoading is set so the attribute is omitted in the default case, matching prior behavior.

Platforms 📲

• Web
• Mobile

Type of change 🔍

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested? 🧪

[Enter the tips to test this PR]

Added a regression test asserting the rendered button has aria-disabled="true" while isLoading is true, even without an explicit disabled prop.
Ran the full Button test suite locally — all 146 tests pass; 34 pre-existing "Loading" snapshots were updated to include the new aria-disabled="true" attribute, and no other snapshots changed.

• Unit Test
• Snapshot Test

Checklist: 🔍

• My code follows the contribution guide of this project Contributing Guide
• Layout matches design prototype: FIGMA
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Screenshots 📸

[Upload your screenshots here]

N/A

Before	After