abstract class CompanyBaseRequest extends FormRequest
{
    ...
    public function rules()
    {
        return [
            'name' => ['required', 'string', 'max:255'],
            'category_id' => ['required', 'exists:company_categories,id'],
            'short_description' => ['required', 'string', 'max:2000'],
            'video' => ['nullable', 'file', 'mimes:mp4', 'max:30000'],
        ];
    }
}

And then two subclasses:

class CompanyStoreRequest extends CompanyBaseRequest
{
    ...
    public function rules()
    {
        return array_merge(parent::rules(), [
            'logo' => ['required', 'file', 'mimes:png,jpg,jpeg', 'max:1024'],
        ]);
    }
}

class CompanyUpdateRequest extends CompanyBaseRequest
{
    ...
    public function rules()
    {
        return array_merge(parent::rules(), [
            'logo' => ['nullable', 'file', 'mimes:png,jpg,jpeg', 'max:1024'],
        ]);
    }
}