[Nova] Disable Uploads for Linux Wheels from CircleCI

[osalpekar]

Documenting my steps here so that others can reference while migrating repos to Nova. I might have done something wrong here so @abhinavarora and @Nayef211 feel free to correct me here:

1. Create py3.8 conda env and install jinja2.
2. For the job you are trying to migrate (for example, build_linux_wheels), find out if any jobs depend on this job.
3. If there are no dependent jobs, you can remove the job definition from the config.yml.in file and tweak regenerate.py to not generate the build + upload workflows in config.yml for that job.
4. If there are dependent jobs, use your discretion. In this case, build_docs was a dependent job on the python 3.8 Linux Wheels build. So I completely removed the Linux Wheels jobs for all other python versions, and kept around the py3.8 version just so the build_docs job will work. For the py3.8 version, I disabled upload and smoke tests. All of this was done in the regenerate.py script.
5. Run python3.8 regenerate.py. Ensure the workflows you don't want are removed. Put up the PR. Ensure that the right things are run and jobs you want to disable are not.

[DanilBaibak]

LGTM