Strange things in session folder

I'm new to laravel and want to know what can delete session files in storage/framework/sessions/*

I have a project that is put on hold. That means that I haven't done anything for two months. No coding, no logging in. And I put that project on git. I have also script that checks all my projects if I forget to commit and push something. So two months - nothing. Today my script alert me for uncommitted changes. And that changes was deleted session files in my laravel project.

My question is how those files can be deleted without using that project? If there is no way of deleting session files without logging in, then may be someone else is trying to use my project. Although only I know the address.