Fix 'publish_TestPyPI' CI job

[CasperWA]

Fixes #331

Use github.event_name instead of github.event.
See the difference here.

Tested this in my fork, it ran for a push to my master branch (which is the top CI run requirement), see the action run here.
Never mind that it fails, this is due to my fork not having the correct secret.

The last two tests that this works lies in making sure that:

• The job 'publish_TestPyPI' is skipped for this PR, and
• The job is not skipped when merging this in and that it succeeds (naturally).

[CasperWA]

Note: Another solution to this would be to factor out the 'publish_TestPyPI' into a separate CI yml file, which only runs for pushes into 'master'?

This is essentially how we used to do it, and is a way I would prefer, since the current setup introduces some obscurity.

[codecov]

Codecov Report

Merging #337 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #337   +/-   ##
=======================================
  Coverage   90.56%   90.56%           
=======================================
  Files          55       55           
  Lines        2268     2268           
=======================================
  Hits         2054     2054           
  Misses        214      214           

Flag	Coverage Δ
#unittests	90.56% <ø> (ø)

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[CasperWA]

Note: Another solution to this would be to factor out the 'publish_TestPyPI' into a separate CI yml file, which only runs for pushes into 'master'?

This is essentially how we used to do it, and is a way I would prefer, since the current setup introduces some obscurity.

@shyamd as you merged this, could you possibly also make a comment on this (my comment)?

[ml-evs]

Still fails:

HTTPError: 403 Client Error: The user 'ShyamD' isn't allowed to upload to project 'optimade'. See https://test.pypi.org/help/#project-name for more information. for url: https://test.pypi.org/legacy/

Who owns the test pypi package?

[shyamd]

It properly skips, but doesn't work in the push.

[shyamd]

@CasperWA , you own the Test PYPI package. I might have overwritten your secret with my key. Can you generate an API token for the Test server and set it in the secrets?