The best way to achieve bug-free code is to ban AI LLMs from creating code in your project.
First of all, writing code is considerably easier than reviewing code. With LLMs you can hope to automate the easy bit while making the hard bit harder because there is nobody to ask why they chose to do X two months ago. Also, there will be either zero documentation, unintelligible documentation, or plain wrong documentation.
Secondly, LLMs are currently pretty poor at writing code. LLMs have no intelligence, they just rehash what they have found elsewhere. Their proposed code is therefore full of ancient code styles that have long fallen out of favour, full of approaches that were thought to be safe fifteen years ago but have long since been replaced by better practices, or approaches that have never been safe but just worked (as in: passed a functionality test) in a time when security was an afterthought.
And that's just the coding. At the moment Open Source projects (and probably closed source projects too but they won't tell us) are bombarded with ChatGPT gibberish masquerading as bug reports because people want to achieve kudos, or get a bug bounty. Just spray and pray GPT diarrhoea at dev teams and see what sticks. At the moment LLMs are hard at work making software quality worse.
I'm not saying LLMs (or even AI at some point) can never play a role in serious quality software development (I can see how it could theoretically work but the snake oil salesmen have no incentive to focus on quality) but I suspect that is a good few years off. If it ever happens.