Why does the Linux kernel not use rust?

I have heard that the Linux Kernel uses rust. I don't know much about the programming language except that it has the potential to run faster than C. According to websites Rust is more safe than C because it's compilation process detects errors and imposes some restrictions. However if the compiled code does not follow those guidelines. You can compile Rust in unsafe mode which is more or less C except not C. However when I looked up if Linux uses Rust the websites that told that C uses Rust. They are lying because I checked the Linux Kernel on GitHub and there is a place in the repository or project that says what percentage of code is being used in the repository or project and it says nothing for Rust. According to the information I got about Rust and C, Rust seems to be much better because it is safer and runs faster than C in some situations. If that is so then why does Rust not use the Linux Kernel? **Please correct me if I am wrong about my claims of Rust and C. I have never coded before but I like comparing languages to see which one is the best. Also if the only reason why the Linux Kernel does not use Rust is because all the Linux developers would have to learn a new language or get fired just say that.**