ucx-py: stop development and package publishing

[bdice]

Description

RAPIDS 25.08 is the final release to include ucx-py packages (the final version will be 0.45):

• https://docs.rapids.ai/notices/rsn0050/
• https://anaconda.org/rapidsai/ucx-py
• https://pypi.org/project/ucx-py-cu12/#history

This issue tracks the work of removing ucx-py references across RAPIDS from the 25.10 release forward.

The task list below is copied from #197.

Benefits of this work

• reduces maintenance burden and complexity
• clarifies the development status of ucx-py

Acceptance Criteria

• no remaining unnecessary references to ucx-py across RAPIDS projects

Approach

Look for references to ucx-py: (GitHub search)

• publish an RSN saying ucx-py is deprecated (Dropping UCX-Py project in v25.10 docs#640)
• stop publishing nightly packages (Drop ucx-py from nightly builds/tests workflows#91)
• remove entries in rapids-metadata (Add 25.10 rapids-metadata#59)
• update RSN to "completed" (RSN 50: dropping ucx-py (mark completed) docs#686)
• remove ucx-py from rapids meta-package -- not needed, as it was not included
• remove from devcontainers -- not needed, as it was not included
• remove from user-facing docker images -- not needed, as it was not included
• deployment (Update instructions to UCXX deployment#611)
• rapids-reviser (https://github.com/rapidsai/rapids-reviser/pull/93)
• release-scripts (https://github.com/rapidsai/release-scripts/pull/38)
• other miscellaneous references in comments, docs, etc.
  • cuvs (Remove UCX-Py/UCXX from release script NVIDIA/cuvs#1331)
  • docs (Replace UCX-Py with UCXX in maintainers page docs#682)
  • shared-actions (Remove UCX-Py shared-actions#76)
  • ucx-wheels (Remove UCX-Py reference from README ucx-wheels#29)

[jameslamb]

RAPIDS 25.08 is the final release to include ucx-py packages (the final version will be 0.45):

Thanks for opening this! I just set the target on this to release v25.10:

That's helpful for arranging things in the by-release view of this (private) board: https://github.com/orgs/rapidsai/projects/116/views/15

[pentschev]

I started a UCX-Py issue with tasks that need to be done for its complete deprecation: rapidsai/ucx-py#1160

[jakirkham]

Approved and merged James' RSN update

Anything else still needed here? Or are we good to close?

[jameslamb]

Yes we can close this now that rapidsai/docs#686 is merged.