Pin cargo-chef to 0.1.75 to fix Docker build on rustc 1.85.0

cargo-chef 0.1.76+ switched to guppy, which transitively pulls in
cargo_metadata@0.23.1, cargo-platform@0.3.2, and target-spec@3.5.7,
all requiring rustc 1.86+.

Author: penberg

Dockerfile

@@ -15,7 +15,7 @@ RUN cat rust-toolchain.toml | grep "channel" | awk '{print $3}' | sed 's/\"//g'
     && rustup update $(cat toolchain.txt) \
     && rustup default $(cat toolchain.txt) \
     && rm toolchain.txt rust-toolchain.toml \
-    && cargo install cargo-chef --locked
+    && cargo install cargo-chef --version 0.1.75 --locked
 
 FROM chef AS planner
 ARG BUILD_DEBUG=false