message: make build image commit has configurable
diff: @@ -50,9 +50,6 @@ ARG rust_nightly_version=nightly-2022-03-29
  ARG cargo_udeps_version=0.1.27
  ARG cargo_hack_version=0.5.12
  ARG cargo_minimal_versions_version=0.1.3
  -# If the `checkout_smithy_rs_tools` arg is set to true, then the Dockerfile will acquire the tools
  -# source code by checking out awslabs/smithy-rs/main rather than copying them from the local directory.
  -ARG checkout_smithy_rs_tools=false
  ENV RUSTUP_HOME=/opt/rustup \
  CARGO_HOME=/opt/cargo \
  PATH=/opt/cargo/bin/:${PATH} \
  @@ -90,6 +87,11 @@ RUN set -eux; \
  cargo --version; \
  cargo +${rust_nightly_version} --version;
  COPY . tools/
  +# when `checkout_smithy_rs_tools` is set to true, this commit will be checked out
  +ARG smithy_rs_commit_hash=main
  +# If the `checkout_smithy_rs_tools` arg is set to true, then the Dockerfile will acquire the tools
  +# source code by checking out awslabs/smithy-rs/main rather than copying them from the local directory.
  +ARG checkout_smithy_rs_tools=false
  RUN set -eux; \
  cargo +${rust_nightly_version} install cargo-udeps --version ${cargo_udeps_version}; \
  cargo install cargo-hack --version ${cargo_hack_version}; \
  @@ -97,6 +99,7 @@ RUN set -eux; \
  if [[ "${checkout_smithy_rs_tools}" == "true" ]]; then \
  git clone https://github.com/awslabs/smithy-rs.git; \
  cd smithy-rs; \
  + git checkout ${smithy_rs_commit_hash}; \
  fi; \
  cargo install --path tools/publisher; \
  cargo +${rust_nightly_version} install --path tools/api-linter; \
  