Update Weaviate examples for client 4.16 API

[henry3260]

What

Update Weaviate system example Dags for the Python client 4.16 vector configuration API.

The examples now use vector_config / Configure.Vectors instead of the deprecated
vectorizer_config / Configure.Vectorizer, and explicitly use
Configure.Vectors.self_provided() where vectors are supplied by the Dag.

The provider now requires weaviate-client>=4.16.4,!=4.16.7 to use the new API
while avoiding the documented 4.16.0-4.16.3 invalid-properties behavior and the
known 4.16.7 protobuf issue.

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

---

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• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
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---

Important

🛠️ Maintainer triage note for @henry3260 · by @potiuk · 2026-06-17 14:51 UTC

Helpful heads-up from the maintainers — please address before this PR can be reviewed:

• Static / docs checks failing (CI image checks / Static checks). Run them locally with prek run --all-files (or pre-commit run --all-files) and push the fixes.
• Failing test jobs: Additional CI image checks / Check that image builds quickly. Reproduce and fix locally, then push.
• See the Pull Request quality criteria.

The ball is in your court — you've been assigned to this PR. Fix the above, then mark it Ready for review.

_{Automated triage — may be imperfect; a maintainer takes the next look.}

[henry3260]

cc @Lee-W

[github-actions]

uv.lock on main just moved via #68105 ("Bump pydantic-ai-slim to resolve dependabot"), commit db9c9cc and this PR currently conflicts.

Quickest fix:

git fetch upstream main && git rebase upstream/main
rm uv.lock && uv lock
git add uv.lock && git rebase --continue
git push --force-with-lease

Automated nudge — ignore if you're not ready to rebase. This comment is updated in place on future uv.lock bumps.