fix: update phpstan level to 8 and improve commands

[Morgy93]

This pull request improves dependency injection usage, error handling, and input sanitization across several console commands. The main focus is on replacing direct usage of Magento's ObjectManager with constructor-injected dependencies, which enhances code testability and maintainability. Additionally, it improves validation and error reporting in theme-related commands.

Dependency Injection Improvements:

• InspectorCommand.php: Replaces direct ObjectManager usage for ScopeConfigInterface with constructor injection, and updates corresponding usage in the isInspectorEnabled() method. [1] [2] [3]
• CheckCommand.php: Injects ResourceConnection and ClientFactory via the constructor, removing ObjectManager calls in methods that require database and HTTP client access. Updates affected methods to use the injected dependencies. [1] [2] [3] [4]

Input Validation and Error Handling:

• BuildCommand.php: Adds a check for a missing theme path and reports an error if the path is not found, preventing further execution.
• WatchCommand.php: Adds error reporting if no suitable builder is found for the given theme, returning a failure status.

Sanitization Enhancements:

• BuildCommand.php & CleanCommand.php: Improves the sanitizeTermValue and sanitizeAlphanumericValue methods to handle cases where preg_replace returns null, ensuring robust input validation. [1] [2] [3] [4]

Static Analysis Configuration:

• phpstan.neon: Increases the PHPStan analysis level from 7 to 8, enforcing stricter static analysis.