refactor: [IOPLT-1575] Migrates to expo-linear-gradient

[LeleDallas]

Short description

This pull request migrates the codebase from using react-native-linear-gradient to expo-linear-gradient for gradient components across both the main app and the design system.

List of changes proposed in this pull request

• Replaced react-native-linear-gradient with expo-linear-gradient in related project files;
• Apply expo-linear-gradient prop names and types to match (e.g., replaced angle/angleCenter/useAngle with start/end vectors, and explicitly typed colors and locations arrays)

How to test

Check each edited gradient component and ensure the behavior has unchanged

[github-actions]

PR Title Validation for conventional commit type

✅ All good! PR title follows the conventional commit type.

[github-actions]

Jira Pull Request Link

This Pull Request refers to Jira issues:

• IOPLT-1575

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.77%. Comparing base (9644de0) to head (a41788e).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8463      +/-   ##
==========================================
- Coverage   63.78%   63.77%   -0.01%     
==========================================
  Files        1978     1978              
  Lines       37608    37608              
  Branches     6360     6360              
==========================================
- Hits        23989    23986       -3     
- Misses      12242    12245       +3     
  Partials     1377     1377              

Files with missing lines	Coverage Δ
apps/main-app/ts/components/ui/IOListView.tsx	68.57% <ø> (ø)
apps/main-app/ts/components/ui/IOScrollView.tsx	82.53% <ø> (ø)
...code/components/BarcodeScanBaseScreenComponent.tsx	81.13% <ø> (ø)
...tures/itwallet/common/components/ItwBrandedBox.tsx	87.17% <100.00%> (ø)
...llet/common/components/ItwCredentialClaimsCard.tsx	91.66% <ø> (ø)
...et/trustmark/components/ItwCredentialTrustmark.tsx	17.24% <ø> (ø)

... and 1 file with indirect coverage changes

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