fix(validity): scope cargo chef prepare to the actual binaries

Without --bin, cargo chef prepare captures a recipe for the entire
workspace (all 12 members), including unrelated scripts/test crates
that pin much newer alloy-* versions (up to 2.0.4, requiring rustc
1.91-1.94). cook then tries to compile that whole graph against
rust:1.85 and fails.

--bin validity --bin clear-stuck-txs makes cargo-chef ignore workspace
members not needed to build those two binaries, matching what the
final cargo build step actually needs.

Author: BlueShells

validity/Dockerfile

@@ -8,10 +8,14 @@ FROM lukemathwalker/cargo-chef:latest-rust-1.85 AS chef
 WORKDIR /build
 
 # Planner stage: compute a dependency-only recipe from the workspace
-# Cargo.toml/Cargo.lock, independent of the rest of the source tree
+# Cargo.toml/Cargo.lock, independent of the rest of the source tree.
+# --bin scopes the recipe to only what validity/clear-stuck-txs actually need —
+# without it, cargo-chef pulls in every workspace member (including unrelated
+# scripts/test crates that depend on much newer alloy-* versions requiring
+# rustc up to 1.94), and `cook` fails trying to compile those against 1.85.
 FROM chef AS planner
 COPY . .
-RUN cargo chef prepare --recipe-path recipe.json
+RUN cargo chef prepare --bin validity --bin clear-stuck-txs --recipe-path recipe.json
 
 # Build stage
 FROM chef AS builder