Dockerfile: bump CADGENBENCH_SHA to 9bd02fb (lazy baseline import)

Picks up the cadgenbench fix that makes `cadgenbench --help` and
`cadgenbench evaluate` work in the eval-only install (no
`[baseline]` extra). Before this bump, the chunk-4 worker's
`python -m cadgenbench.cli evaluate <run_dir>` subprocess died
during argparse setup with `ModuleNotFoundError: No module named
'dotenv'`, flipping every submission to status=failed before any
work happened.

Bumping CADGENBENCH_SHA invalidates the cadgenbench layer in the
Dockerfile cache (Chromium layer + earlier layers stay cached),
so the rebuild is ~2-3 min not the ~5 min cold cycle.

Dockerfile

@@ -44,7 +44,7 @@ RUN pip install --no-cache-dir playwright \
 
 # cadgenbench from the Public GitHub repo, pinned to a commit. Bumping
 # CADGENBENCH_SHA is the one-line path to picking up a new cadgenbench.
-ARG CADGENBENCH_SHA=d88e39c
+ARG CADGENBENCH_SHA=9bd02fb
 RUN pip install --no-cache-dir \
         "cadgenbench @ git+https://github.com/huggingface/cadgenbench.git@${CADGENBENCH_SHA}"