Move the check_release.yml to its own workflow

[jtpio]

• Move the check_release step to a separate workflow, so it's easier to see if it passes
• And add an extra step to upload the artifacts built by the releaser, so it's easier to test PRs locally by installing the built wheel from a branch.

[jtpio]

@martinRenou I was wondering if this was maybe ready to be merged?

Having the built artifacts could help test changes from other PRs more easily, for example #2178.

[martinRenou]

Thanks!

[krassowski]

test_check does not pass because it is waiting for check_release:

nbconvert/.github/workflows/tests.yml

Lines 161 to 170 in 6e5fdb3

	tests_check: # This job does nothing and is only used for the branch protection
	if: always()
	needs:
	- coverage
	- test_lint
	- test_minimum_versions
	- test_prereleases
	- check_links
	- check_release
	- test_sdist

It would need to be removed from it and added as a separate protection rule

[jtpio]

It would need to be removed from it and added as a separate protection rule

Done in 5541bdb.

However I don't have access to the repo settings to enable the protection rule in case we want to add one (not sure if this may have an impact on the releaser though).