Cleanup tests

[lord-of-the-lost]

Improve test naming and closure syntax in SnapKitTests

Description

This PR improves the readability and maintainability of test files by:

• Replacing non-descriptive variable names (v1, v2, vc) with meaningful names (firstView, secondView, viewController)
• Simplifying closure syntax by removing redundant (make) -> Void in and using $0 shorthand
• Removing unnecessary return statements in closures
• Making the test class final to improve performance
• Removing empty setUp and tearDown methods
• Removing redundant self references where not required by Swift

Why is this important?

1. Better Code Readability: Descriptive variable names make tests easier to understand and maintain, especially for new contributors
2. Modern Swift Syntax: Using $0 shorthand, removing redundant type annotations and unnecessary self references follows Swift best practices
3. Performance: Making the test class final provides a small performance benefit
4. Consistency: Following Swift's style guidelines for property access makes the codebase more consistent

Testing

All tests continue to pass with these changes. No functional changes were made to the test logic.