Bump Python packages to 0.9.0.dev0

[ciaranra]

Coordinated Python version bump 0.8.0.dev8 → 0.9.0.dev0, prepping the release that flips HybridEngine's default classical interpreter to Rust (#347).

Why a minor bump: the default-interpreter switch is a user-visible default-behavior change; in the 0.x convention the minor number is the signal for that (additive-only would be a patch/dev increment). It gives the release note — and the cinterp="python" escape hatch — a clear version boundary.

What's bumped (every occurrence, verified zero stragglers):

• version = in all 11 workspace pyproject.tomls (root meta-package, pecos-rslib, -llvm, -cuda, -exp, quantum-pecos, 5 selene plugins)
• Exact-version internal pins: root quantum-pecos[cuda12/13]==... (4) and quantum-pecos's pecos-rslib==... / pecos-rslib-llvm==...
• uv.lock + exp/zluppy/uv.lock regenerated — diffs are version-lines-only (11 and 3 respectively, no dependency churn)
• docs/user-guide/cli.md example output

Verification: git grep 0.8.0.dev8 → no matches; uv lock --check passes; CI-standard sync rebuilds cleanly and pecos.__version__ reports 0.9.0.dev0 with the Rust default interpreter intact.

After merge: tag py-0.9.0.dev0 (or at cut time) to build the tagged artifact bundle; publishing remains manual from the collected artifacts.

[ciaranra]

Also updated scripts/publish-wheels.sh to publish pecos-rslib-llvm (before quantum-pecos, which pins it exactly). The script predated the LLVM split — it would have silently skipped the llvm wheels, leaving quantum-pecos==0.9.0.dev0 uninstallable from PyPI (pecos-rslib-llvm has never been published; note the wheel bundle dir name is dist/pecos-rslib-llvm/, which the script already resolves).