Update to PHP 8.4 and new dependencies

[dbellettini]

• Upgrade PHP 8.4
• Upgrade Dependencies
• Upgrade code with rector
• Fix Coding Standards

[Copilot]

Pull Request Overview

This PR upgrades the codebase to PHP 8.4 compatibility with comprehensive updates to modern PHP language features and coding standards. The upgrade includes dependency updates, automated code modernization via Rector, and coding standards fixes.

• Update type declarations and return types for PHP 8.4 compatibility
• Modernize class properties with constructor promotion and readonly modifiers
• Replace legacy syntax with modern PHP 8+ alternatives
• Fix coding standards and improve type safety throughout

Reviewed Changes

Copilot reviewed 131 out of 133 changed files in this pull request and generated 3 comments.

File	Description
src/Timeless/*.php	Add type declarations, use constructor promotion, modernize DateTime usage
src/Sink/BlackHole.php	Add Stringable interface, improve type declarations
src/Recruiter/*.php	Extensive type safety improvements, constructor promotion, modern syntax
spec/**/*.php	Update test methods with void return types, modernize assertions

Comments suppressed due to low confidence (1)

src/Recruiter/Workable/ExitsAbruptly.php:8

• The class name was changed from ThrowsFatalError to ExitsAbruptly, but the behavior implementation calls exit(-1) instead of throwing a fatal error. The new name better reflects the actual behavior, but this change should be verified for consistency with expected behavior in tests and usage.

class ExitsAbruptly implements Workable