guess we haven't bumped this number in a while huh

Signed-off-by: clux <sszynrae@gmail.com>

README.md

@@ -1,7 +1,7 @@
 # kube-rs
 
 [![Crates.io](https://img.shields.io/crates/v/kube.svg)](https://crates.io/crates/kube)
-[![Rust 1.81](https://img.shields.io/badge/MSRV-1.81-dea584.svg)](https://github.com/rust-lang/rust/releases/tag/1.81.0)
+[![Rust 1.91](https://img.shields.io/badge/MSRV-1.91-dea584.svg)](https://github.com/rust-lang/rust/releases/tag/1.91.0)
 [![Tested against Kubernetes v1.28 and above](https://img.shields.io/badge/MK8SV-v1.28-326ce5.svg)](https://kube.rs/kubernetes-version)
 [![Best Practices](https://bestpractices.coreinfrastructure.org/projects/5413/badge)](https://bestpractices.coreinfrastructure.org/projects/5413)
 [![Discord chat](https://img.shields.io/discord/500028886025895936.svg?logo=discord&style=plastic)](https://discord.gg/tokio)