[v3-2-test] Fix CARGO_HOME location for airflow user builds (#64899) (#64914)

Move CARGO_HOME from /usr/local/cargo to /home/airflow/.cargo so that
cargo builds work correctly when running as the airflow user, avoiding
permission issues with the system-wide cargo directory.
(cherry picked from commit e62a12d)

Author: potiuk

Dockerfile

@@ -1874,7 +1874,7 @@ ENV DEV_APT_DEPS=${DEV_APT_DEPS} \
 ARG PYTHON_LTO
 
 ENV RUSTUP_HOME="/usr/local/rustup"
-ENV CARGO_HOME="/usr/local/cargo"
+ENV CARGO_HOME="/home/airflow/.cargo"
 ENV PATH="${CARGO_HOME}/bin:${PATH}"
 
 COPY --from=scripts install_os_dependencies.sh /scripts/docker/