chore: release v0.19.0

[github-actions]

🤖 New release

• differential-dataflow: 0.18.0 -> 0.19.0 (⚠ API breaking changes)
• differential-dogs3: 0.18.0 -> 0.19.0

⚠ differential-dataflow breaking changes

--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/inherent_method_missing.ron

Failed in:
  PointStamp::into_vec, previously in file /tmp/.tmpXLsX4G/differential-dataflow/src/dynamic/pointstamp.rs:75

Changelog

differential-dataflow

0.19.0 - 2026-02-06

Other

• Back Pointstamp with SmallVec (#661)
• Correct chainless lower bound determination (#660)
• Exchange columns more efficiently (#656)
• fix broken example link (#654)

differential-dogs3

0.18.0 - 2025-10-23

Other

• Updates for timely 0.25 (#647)
• Extract VecCollection from Collection (#651)
• Correct some clippy nit (#649)

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This PR was generated with release-plz.