Auto merge of #116225 - Kobzol:newbors-integration, r=Mark-Simulacrum

Add integration for new bors

I think that the best way to test the [new bors](https://github.com/rust-lang/bors/tree/staging) implementation is to start using it in the wild. This PR integrates this repo with the bot (some more integration has to be done externally through GitHub). For now, I would suggest to integrate it e.g. under the ``@borsnew`` name, and start testing its try build functionality. The bot cannot do merges or approvals yet, and it doesn't touch `master` in any way, so hopefully it shouldn't cause any troubles for this repo.

r? `@Mark-Simulacrum`

Author: bors