Fix non-working Dockerfile for build process

Details:
- Initialized git submodules in binaryen installation process.
- Altered Rust installation to use the version specified in ./rust-toolchain, instead of the default stable version.
- Installed additional components and target using ./rust-toolchain version.
- Removed rust-toolchain after installation to maintain a clean working directory.

Dockerfile

@@ -41,6 +41,7 @@ RUN curl -sSf https://apt.llvm.org/llvm.sh | bash -s -- 12 && \
 # Install wasm-opt from binaryen
 RUN git clone --depth 1 --branch version_114 https://github.com/WebAssembly/binaryen.git /binaryen && \
   cd /binaryen && \
+  git submodule update --init && \
   cmake . && \
   make -j$(nproc) && \
   make install && \
@@ -50,11 +51,15 @@ RUN git clone --depth 1 --branch version_114 https://github.com/WebAssembly/bina
 RUN useradd -ms /bin/bash builduser
 USER builduser
 
-# Install Rust stable
+# Install Rust (using ./rust-toolchain version)
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | bash -s -- -y \
-    --default-toolchain stable \
-    --profile minimal \
-    --component clippy,rustfmt,rust-src \
-    --target wasm32-unknown-unknown
+    --profile minimal
+# Install additional components and target (using ./rust-toolchain version)
+WORKDIR /home/builduser/
+COPY rust-toolchain .
+ENV PATH=/home/builduser/.cargo/bin:$PATH
+RUN rustup component add clippy rustfmt rust-src
+RUN rustup target add wasm32-unknown-unknown
+RUN rm rust-toolchain
 
 CMD Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 & export DISPLAY=':99.0' && bash