prefer system install of UCX in devcontainers, update outdated RAPIDS references

[jameslamb]

Contributes to rapidsai/build-planning#118

Proposes the following changes for pip devcontainers:

• prefer system installation of ucx to the one provided by the libucx-cu{11,12} wheels (ref: prefer system installs of UCX libraries when using RAPIDS wheels devcontainers#421 (comment))

And some other related changes noticed while doing that:

• update lingering 24.* references to 25.02

Notes for Reviewers

How I tested this

Relying on CI for most things. Double-checked that update-version.sh would have caught the one lingering 24.12 reference like this:

./ci/release/update-version.sh '25.02.00'
git grep -E '24\.'

[copy-pr-bot]

Auto-sync is disabled for draft pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

[jameslamb]

/ok to test

[bdice]

/merge