Add spack clean command to install step in Dockerfile

Author: wdconinc

containers/eic/Dockerfile

@@ -106,6 +106,7 @@ export CCACHE_DIR=/ccache
 mkdir -p /var/cache/spack/blobs/sha256/
 find /var/cache/spack/blobs/sha256/ -ignore_readdir_race -atime +7 -delete
 spack ${SPACK_FLAGS} install ${SPACK_INSTALL_FLAGS}
+spack clean --downloads --stage
 ccache --show-stats
 ccache --zero-stats
 EOF
@@ -240,6 +241,7 @@ RUN --mount=type=cache,target=/ccache,id=ccache-${TARGETPLATFORM}              \
 set -e
 export CCACHE_DIR=/ccache
 spack ${SPACK_FLAGS} install ${SPACK_INSTALL_FLAGS}
+spack clean --downloads --stage
 spack gc --yes-to-all go go-bootstrap rust rust-bootstrap py-setuptools-rust py-maturin
 ccache --show-stats
 ccache --zero-stats