Rust 1.91.1: Apply CI changes, Update target code to compile

.github/containers/release/Dockerfile

@@ -0,0 +1,40 @@
+FROM ubuntu:22.04 as base
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt update && \
+    apt -y install \
+        build-essential \
+        cmake \
+        curl \
+        git \
+        libssl-dev \
+        ninja-build \
+        pkg-config \
+        python3 \
+        zlib1g-dev
+
+RUN curl -sSf https://sh.rustup.rs | sh -s -- -y
+ENV PATH="/root/.cargo/bin:${PATH}"
+ENV RISC0_HOME="/risc0"
+
+WORKDIR /src
+
+FROM base AS builder
+COPY . .
+
+RUN ls -al rust/.git
+
+WORKDIR /src/risc0
+RUN --mount=type=cache,id=release,target=/root/.cache \
+  --mount=type=cache,id=release,target=/root/.cargo,from=base,source=/root/.cargo \
+  cargo build --bin rzup
+
+RUN mkdir -p /risc0
+
+RUN --mount=type=cache,id=release,target=/root/.cache \
+  --mount=type=cache,id=release,target=/root/.cargo,from=base,source=/root/.cargo \
+  target/debug/rzup build rust --path /src/rust
+
+FROM scratch AS export
+COPY --from=builder /risc0/toolchains/ /