Coverage upload failed (HTTP 404)

Running actions/upload-code-coverage fails with the following error message:

Error: Coverage upload failed (HTTP 404): Not Found. To treat upload errors as warnings, add 'fail-on-error: false' to the action inputs.
Error: Process completed with exit code 1.

The action is configured as such:

- name: upload coverage report
  if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
  uses: actions/upload-code-coverage@v1
  with:
    file: coverage/coverage.xml
    language: ruby
    label: coverage

And these are the recognized parameters the action runs with:

commit_oid: 578fc6d9cad30bcc31100837764e1fc08b50ad11
ref: refs/heads/remove-codecov
pr_number: 256
language: ruby
label: coverage
file: coverage/coverage.xml (8687 bytes)

Start by reproducing the actions/upload-code-coverage@v1 workflow step with coverage/coverage.xml and the listed commit, ref, pull request, language, and label parameters. Trace the HTTP 404 response and compare it with the action's expected upload inputs. Done means the Ruby coverage report uploads successfully without the workflow failing.