fix: resource management issues - empty Dispose and missing nullability

[thomhurst]

Description

Empty Dispose in EventReceiverOrchestrator.cs (Lines 550-553)

public void Dispose() { /* No longer need to dispose... */ }

Class implements IDisposable but has no cleanup logic. Should either remove the interface or document why it's retained.

Missing Nullability Annotations in PropertyInjector.cs

Methods like InjectPropertiesRecursiveAsync accept TestContextEvents events without ? nullability, but line 105 checks if (events == null). The contract is unclear — parameter should be marked nullable or validated with ArgumentNullException.

Suggested Fix

• Remove IDisposable from EventReceiverOrchestrator if no cleanup is needed
• Add consistent nullability annotations to PropertyInjector parameters