Update rust Docker tag to v1.86.0 (#643)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

federation/subgraphs/Dockerfile.rust

@@ -1,4 +1,4 @@
-FROM rust:1.85.1 as builder
+FROM rust:1.86.0 as builder
 
 WORKDIR /usr/src/subgraph
 COPY Cargo.toml Cargo.lock ./