fix(libero-plus): flatten deep path prefix from Sylvest/LIBERO-plus assets.zip

The 6.4 GB zip ships with every entry prefixed by
`inspire/hdd/project/embodied-multimodality/public/syfei/libero_new/release/dataset/LIBERO-plus-0/assets/...`
(the author's internal filesystem layout, not the layout the LIBERO-plus
README promises), so the previous `unzip -d ${LIBERO_PLUS_ROOT}/` created
`${LIBERO_PLUS_ROOT}/inspire/.../assets/` — robosuite still opened
`${LIBERO_PLUS_ROOT}/assets/scenes/tabletop_table_Cobblestone01_GLOSS_6K.xml`
and hit the same FileNotFoundError.

Extract to a scratch dir, then `mv` the nested `assets/` subtree to the
expected location. Verified the target file exists in the zip central
directory under that exact prefix.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/Dockerfile.benchmark.libero_plus

@@ -107,7 +107,9 @@ RUN python${PYTHON_VERSION} -c "\
 from huggingface_hub import hf_hub_download; \
 hf_hub_download(repo_id='Sylvest/LIBERO-plus', repo_type='dataset', \
                 filename='assets.zip', local_dir='/tmp/libero-plus-dl')" && \
-    unzip -q /tmp/libero-plus-dl/assets.zip -d ${LIBERO_PLUS_ROOT}/ && \
+    unzip -q /tmp/libero-plus-dl/assets.zip -d /tmp/libero-plus-dl/extract && \
+    mv /tmp/libero-plus-dl/extract/inspire/hdd/project/embodied-multimodality/public/syfei/libero_new/release/dataset/LIBERO-plus-0/assets \
+       ${LIBERO_PLUS_ROOT}/assets && \
     rm -rf /tmp/libero-plus-dl
 RUN mkdir -p /home/user_lerobot/.libero && \
     printf "assets: ${LIBERO_PLUS_ROOT}/assets\nbddl_files: ${LIBERO_PLUS_ROOT}/bddl_files\ndatasets: ${LIBERO_PLUS_ROOT}/../datasets\ninit_states: ${LIBERO_PLUS_ROOT}/init_files\n" \