They also occasionally organize live tournaments lasting for a week or two, which introduce a new game. From the names like fall-challange-2021 and spring-challange-2021 I assume those happen no more than every 6 months.
In general the ones that are in form of temporary contests often support many languages due to same reason I mentioned before. One thing to watch out that due to sandboxing reasons and the platform needing to compile your code any third party libraries are usually not available. This might be slightly more painful for Rust and their crate based ecosystem.
https://en.wikipedia.org/wiki/AI_Challenge series used to be good but they are not organizing new ones. VK organizes yearly contests called "Russian AI cup" with very similar format as AI_Challange https://en.wikipedia.org/wiki/Russian_AI_Cup . Although participation currently might be messy due to the current political situation. Also the website isn't fully translated to English. List of old contents can be found here https://cups.online/en/contests/?category=ai&utm_campaign=to...