Upgrade zig version to 0.15.2

[DaviRain-Su]

Description

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)
• Documentation update
• Performance improvement
• Code refactoring
• Test improvement

Testing

• All existing tests pass (zig build test)
• Added new tests for the changes
• Manual testing performed

Checklist

• My code follows the Zig style guide (zig build fmt)
• Linting passes (zig build lint)
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• 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

Related Issues

Closes #

Additional Notes

[DaviRain-Su]

dep: jsign/zig-eth-secp256k1#5