clarify CI job names

[jameslamb]

Fixes #769

Notes for Reviewers

How this works

In this repo, we have a pattern roughly like this for CI:

# pr.yaml
name: ci
...
jobs:
  docker:
    uses: ./.github/workflows/build-test-publish-images.yml

# build-test-publish-images.yaml
name: build and publish imgs workflow
...
jobs:
  build-rapids:
    strategy:
      matrix: ${{ fromJSON(needs.compute-matrix.outputs.MATRIX) }}
    uses: ./.github/workflows/build-rapids-image.yml

# build-rapids-image.yml
name: Build and push image variant
...
jobs:
  build:
    strategy:
      matrix:
        ARCH: ${{ fromJSON(inputs.ARCHES) }}
        CUDA_VER: ["${{ inputs.CUDA_VER }}"]
        LINUX_VER: ["${{ inputs.LINUX_VER }}"]
        PYTHON_VER: ["${{ inputs.PYTHON_VER }}"]
        RAPIDS_VER: ["${{ inputs.RAPIDS_VER }}"]
...

Each stage in that chain of workflow calls adds something to the full job name. Like this:

ref: https://github.com/rapidsai/docker/actions/runs/16297798451/job/46024115023

ref: #774

[gforsyth]

Nice! This makes the job summary much clearer. And thanks for the excellent primer in the PR description.

[jameslamb]

Thanks for reviewing!

[jameslamb]

/merge