fix(images): drop the release cooldown from the notebooks workspace

infra-ci's notebooks build failed on the branch: pypi.nvidia.com serves
cudf-polars-cu12 (and its cu12 deps) without upload dates, so under
UV_EXCLUDE_NEWER every release is filtered out ("no versions of
cudf-polars-cu12"). uv has no per-package opt-out for a date-less index
(`exclude-newer-package` takes a date, and dated cutoffs still drop
undated files), so this image goes back to resolving without a
cooldown; the comment records why. The main lock keeps its cooldown.

Refs #1365

infra/images/notebooks.Dockerfile

@@ -100,11 +100,10 @@ WORKDIR /home/${USERNAME}
 # Bring in the fhirworx marimo wheel from the wheel stage.
 COPY --from=wheel /src/dist/ /tmp/marimo-wheel/
 
-# This workspace resolves at build time (no committed lock), so give it the
-# same 7-day release cooldown as pyproject.toml. ENV, not a one-shot prefix:
-# the workspace lock records the span, and a runtime `uv run` without it
-# would call the lock stale and re-resolve at container start.
-ENV UV_EXCLUDE_NEWER="7 days"
+# No release cooldown here (unlike pyproject.toml's exclude-newer): this
+# workspace pulls cudf-polars-cu12 from pypi.nvidia.com, which publishes no
+# upload dates, so any exclude-newer filters out every release and the build
+# fails. uv has no per-package opt-out for date-less indexes.
 
 # Install python + init workspace venv. Use the local wheel for marimo so
 # the fhirworx frontend ships in the image; no upstream PyPI fetch for