Update Rust version in Dockerfile to 1.91

Signed-off-by: Barnabas Busa <busa.barnabas@gmail.com>

Author: barnabasbusa

reth-rbuilder/Dockerfile.rbuilder

@@ -9,7 +9,7 @@
 ARG FEATURES
 ARG RBUILDER_BIN="rbuilder"
 
-FROM rust:1.89-bookworm AS base
+FROM rust:1.91-bookworm AS base
 ARG TARGETPLATFORM
 
 RUN apt-get update \