Fix async deadlock in synchronization context and integrate AI code review

[qodo-free-for-open-source-projects]

Description

• The current AsyncHelpers.cs implementation has a critical deadlock issue where synchronization context is saved and restored incorrectly, causing async operations to hang
• Loop condition logic in CustomSynchronizationContext.Run is inverted, preventing proper task execution
• Need to establish AI-powered code review workflow to catch defects earlier in the review process
• CI/CD pipeline is running excessive test suites that slow down feedback cycles

Deliverables

• Fix Deadlock: Refactor synchronization context management by moving context setup into Run method and removing save/restore logic from RunSync
• Correct Loop Logic: Fix inverted loop condition and ensure proper exception handling in async callback execution
• AI Review Integration: Implement GitHub Actions workflow that triggers Gemini-based code review on labeled pull requests
• Optimize CI/CD: Remove extended test suites (Integrated, Serializers, DependencyInjection) and keep only core test execution