deps(aieng-platform-onboard): upgrade aieng-platform-onboard to v0.7.3

[fcogidi]

Summary

Update the aieng-platform-onboard package to v0.7.3.

Clickup Ticket(s): N/A

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update
• 🔧 Refactoring (no functional changes)
• ⚡ Performance improvement
• 🧪 Test improvements
• 🔒 Security fix

Changes Made

• Update the aieng-platform-onboard package to v0.7.3.

Testing

• Tests pass locally (uv run pytest aieng-forecasting/tests)
• Type checking passes (uv run mypy <src_dir>)
• Linting passes (uv run ruff check src_dir/)
• Manual testing performed (describe below)

Manual testing details:

Screenshots/Recordings

N/A

Related Issues

N/A

Deployment Notes

N/A

Checklist

• Code follows the project's style guidelines
• Self-review of code completed
• Documentation updated (if applicable)
• No sensitive information (API keys, credentials) exposed