The other answers are excellent, but I want to be a bit of a contrarian and say you should learn Rust. While the number of jobs for it are (relatively) low(er), it is certainly expanding and you'd be surprised at which companies do use Rust (Discord, for example, is starting to move away from Golang to Rust!).
But the main reason is that learning Rust itself will teach you a lot about systems design (/backend) because of its borrow checker. You can try out a lot of ideas and make a lot mistakes and the borrow checker will always be there guide you to a better solution (thereby teaching you in the process).
Also, I wouldn't underestimated how important managing memory (and memory safety) is. While Golang is great in some ways, it doesn't protect you from pushing memory leaks into production. And eventually you'll come upon a scenario where you'll have to make your Python code run faster and the optimizations you'd have to do won't look pretty (or be very Pythontic).
And Rust is freakin fast! If you have Rust, you wouldn't need any other language for the backend (or any other systems level code). Check this blog post: https://blog.discord.com/why-discord-is-switching-from-go-to-rust-a190bbca2b1f?gi=dd8bc5d669d. Discord found that even after spending months optimizing Golang code it still wasn't fast enough. But unoptimized, first-draft Rust code was (is) faster by an order of magnitude!
