Add GitHub Releases

[texodus]

Forked from #2279.

First test tag build for posterity

[texodus]

@tdbgamer This build worked and created a release, but the release has no artifacts (already deleted):

I'm not sure how to interpret the output of the publish task, but clearly the wheels aren't being detected/downloaded even though the script itself is connecting and not erroring because it detects the JS assets (though it does not publish these to the release either):

Running a dry run, this WILL NOT publish. Set the env var COMMIT to publish.
Fetching page 1
Found 0 python folders, expected 17
Found 0 javascript folders, expected 10
Creating GitHub Release v0.0.0-test
Found 0 wheels, expected 17
Found 0 pkgs, expected 10
Uploading to pypi:
	
Uploading to npm:
	perspective-dist
	perspective-viewer-dist
	perspective-viewer-datagrid-dist
	perspective-viewer-d3fc-dist
	perspective-viewer-openlayers-dist
	perspective-workspace-dist
	perspective-jupyterlab-dist
	perspective-cli-dist
	perspective-esbuild-plugin-dist
	perspective-webpack-plugin-dist
Skipping twine/npm upload, marked as dry run.
Set env var COMMIT=1 to run fo real.

[texodus]

Upon closer inspection, I know exactly how to interpret this - we can't call the octokit workflow inspection REST API from within the workflow itself, as the workflow doesn't exist yet. So - looks like this approach to publishing is not going to work as written no matter what, we'll need to port to use the Actions' tasks to move the assets around in CI.