They're probably refering to their strict "No LLM / No AI" policy: https://codeberg.org/ziglang/zig/src/branch/master/README.md...

which applies to contributing to the Zig project.

The "contributor poker" blog post should probably be a required reading to understand where it comes from: https://kristoff.it/blog/contributor-poker-and-ai/

"Anti-AI stance" is painting it with too broad of a brush. You're definitely not breaching any CoC or whatever by using AI for your Zig projects.