uv run --with version bisects quietly grow the uv cache to 10+ GB

Every uv run --no-project --with pkg==X.Y call that resolves a new version unpacks that wheel into ~/.cache/uv. One day of bisecting pandas, NumPy, SciPy, scikit-learn, numba and umap across 3-6 versions each, plus a CPU torch install, left 11 GB there, while the ephemeral environments looked free. On a shared or nearly full disk, check du -sh ~/.cache/uv after a bisect session and run uv cache clean (it freed 10.3 GiB here; the next run just downloads again) or uv cache clean <pkg> for single packages. Pointing UV_CACHE_DIR at a scratch directory for one-off big installs and deleting it afterwards also works.