For my current job, I intentionally applied for a developer role, not a management one. What really helps is to be part of a team which has a decent lead - I knew from the interview that was the case at my current job.
If you don't work 'under' a decent enough lead, you end up picking up the pieces and doing his/her work. So my number one advice would be to make sure you end up working for a strong lead. If you want to stay where you are, you need to have a conversation, but not just about changing roles but also about hiring a lead to take your place. Otherwise I doubt its going to work.
My second point of advice is more of a reassurance: it is not childish to not want to be a manager, its actually very mature to recognize that this is not what makes you happy. I see it as a different job, not a higher one. Good tech managers probably need some tech background, but they don't have to be really good developers - just enough to understand their job as managers. But a good developer isn't by extension a good manager, that is really another skillset.
Somehow becoming a manager has been really sticky for me, you have to work to get it off. Maybe this is because I ended up taking responsibility where others didn't or couldn't, and then other people around me started calling that leadership and thus I became a manager even if I didn't want to.
Now I do understand why managers are getting paid more, its hard and sometimes stressful work to be honest.