Erasing data from a dead iPad Mini

[SOLVED ALREADY, PLEASE IGNORE] I have this iPad Mini which is the very first model (A1432). I have not used it in years since I got a new iPad and now, I'm giving it away to someone who is interested, but before that, I want to make sure that my data has been completely erased and nothing is retrievable. However, my iPad is completely dead - I cannot open it, I only see the low battery symbol. Even after hours of charging, it remains to be on low battery.

Since it's been years since I last used it, I don't remember if I myself had erased my data or done a factory reset. It's not under my Apple ID list of devices anymore - I don't remember either if I had erased the device from the list.

So, what I want to know now is that if in case I did not erase my data from my iPad, can it still be retrieved by someone else even if it's completely dead? Can they retrieve it through the hardware somehow if they disassemble the parts?

All I need is reassurance that my data is unretrievable from a dead old iPad. Thanks!