Bump Rust toolchain to 1.86 (#1886)

Author: svix-jplatte

Diff for: bridge/Dockerfile

@@ -1,5 +1,5 @@
 # Base build
-FROM rust:1.81-slim-bookworm AS build
+FROM rust:1.86-slim-bookworm AS build
 
 RUN apt-get update && apt-get install -y \
     build-essential=12.* \

Diff for: server/Dockerfile

@@ -1,5 +1,5 @@
 # Base build
-FROM rust:1.83-slim-bookworm AS build
+FROM rust:1.86-slim-bookworm AS build
 
 RUN apt-get update && apt-get install -y \
         build-essential=12.* \

Diff for: svix-cli/Dockerfile

@@ -1,5 +1,5 @@
 # Base build
-FROM rust:1.81-slim-bookworm AS build
+FROM rust:1.86-slim-bookworm AS build
 
 RUN apt-get update && apt-get install -y \
     build-essential=12.* \