If you are okay with Rust or C# idk why Go is an issue? Go powers most infrastructure on the internet that we rely on. Docker, Kubernetes, Hugo, Caddy, MinIO, a lot of these are used in backend services so you would never even realize you are using them but you are. I think Go is fine.
I'd prefer Rust as well, but anything with a decent type system is okay. I have bad associations with Java software, but idk if that's the language itself, or enterprise brainworns.
Modern PHP is a strongly typed language, still dynamically typed, but in a way that feels more like static typing. Better than TypeScript for sure if you're not into PhD-level typing hacks, and light years ahead of Ruby, Python, JS, and their ilk.