Fix tool annotation type error when using custom Attributes

[Daanra]

When defining a Tool that uses a custom Attribute, e.g.:

#[MyCustomAttribute]
class CurrentWeatherTool extends Tool
{
   
}

An exception is thrown:

Laravel\Mcp\Server\Tool::{closure:Laravel\Mcp\Server\Tool::annotations():33}(): Argument #1 ($attribute) must be of type Laravel\Mcp\Server\Contracts\Tools\Annotation, MyCustomAttribute given

This is because Tool::annotations() falsely assumes that all Attributes are of type \Laravel\Mcp\Server\Contracts\Tools\Annotation

This pull request attempts to fix this problem by filtering the Attributes before generating the annotations.

P.S. Great work on this package, it's amazing! 🚀