BUG: Docker 2014 image download failure is silent

A bad `manylinux2014-x64` tag was provided for download in an ITKSplitComponents Linux Python test run but the run was marked as successful anyways, even though wheels were missing.

https://github.com/InsightSoftwareConsortium/ITKSplitComponents/actions/runs/3632771768/jobs/6129000489

TODO:
- [x] Add a sanity check to ensure that each expected wheel is in `dist/` before upload to PyPI. If _all_ expected wheels are not build then the run should fail and nothing should upload.
- [ ] Investigate docker option to immediately fail and exit out if image cannot be retrieved.