After reviewing the Texas fees, and your response that the side gig is temporary, I am going to recommend that you do NOT open an LLC for this temporary side gig. If it grows into something more than a temporary thing, then you can reconsider. You don't want to open an LLC if you are just going to have to close it a few months later.
Your liability risk with an IT job is that you will potentially cause harm to a customer's business by accidentally doing something wrong that crashes or otherwise messes with their systems. You yourself can best gauge what the cost of the potential damage you could do if you mess up, and then your insurance agent can advise you of the cost of covering yourself as an individual with liability insurance.