Revise coverage report workflow to generate the report too

The attempt to upload the code coverage report in a separate workflow
has been an exercise in frustration.

The initial plan was to generate the report in the test job of the CI
workflow, save it as an artefact, then download the artefact in the
coverage report workflow and upload it to Code Climate there.

Unfortunately, for this to work the coverage report workflow needs to
check out the revision of the repo on which the report was
generated. Code Climate must associate the coverage report with the
revision that generated so that it can calculate the coverage diffs
for, and the only way in which the Code Climate action can get this is
from the currently checked-out revision.

Frankly, if we're going to have to check the revision out, we may as
well just generate the report in this workflow too, and not mess
around with artefacts. The tests don't take long to run, anyway.

.github/workflows/upload_coverage.yml

@@ -13,18 +13,18 @@ jobs:
 
  steps:
  - uses: actions/checkout@v4
+ with:
+ ref: ${{ github.event.workflow_run.head_branch }}
 
- - name: Fetch coverage report
- uses: actions/download-artifact@v4
+ - name: Set up Ruby
+ uses: ruby/setup-ruby@v1
  with:
- name: coverage-json
- run-id: ${{ github.event.workflow_run.id }}
- github-token: ${{ secrets.GITHUB_TOKEN }}
+ ruby-version: 3.3
+ bundler-cache: true
 
- - name: Upload coverage report to Code Climate
+ - name: Generate and upload coverage report
  uses: paambaati/codeclimate-action@v5
  with:
- coverageLocations: |
- ${{github.workspace}}/coverage.json:simplecov
+ coverageCommand: bundle exec rspec
  env:
  CC_TEST_REPORTER_ID: ${{secrets.CC_TEST_REPORTER_ID}}