Recursively remove additionalProperties for Gemini tools

[Edward144]

Similar to the issue highlighted in #139. Tools containing nested schema objects used by Gemini throw an error for additionalProperties.

"code": 400,
"message": "Invalid JSON payload received. Unknown name \"additionalProperties\"" 

For example in a tool such as:

class ExampleTool implements Tool
{
    public function description(): Stringable|string
    {
        return '';
    }

    public function handle(Request $request): Stringable|string
    {
        return '';
    } 

    public function schema(JsonSchema): array
    {
        return [
            'array' => $schema->array()
                ->items($schema->object([
                    'name' => $schema->string()->required(),
                    'description' => $schema->string()->required(),
                ]))
                ->required(),
        ];
    }
}

To fix this I have updated the MapsTools concern to recursively remove the key from the schema.

[jrking4]

this fixes an issue i am having as well with Gemini tools