Fix "Update lycheeVersion to null"

[thomas-zahner]

lychee-version.yml seems to create PRs with null versions.

This should not happen. Maybe add a check if version is null to prevent the creation of such PRs. Maybe there is another solution.

Note that there is a related workflow & script for the documentation repository: https://github.com/lycheeverse/lycheeverse.github.io/blob/master/bump-lychee.sh
(at first I confused it with that repo & workflow)

[thomas-zahner]

@Arteiii Maybe you could take a look at this if you find the time? It seems like you created the workflow.

[Technetium1]

Make yq exit and fail the workflow if the result is null, then no PR: https://github.com/mikefarah/yq#usage
-e, --exit-status set exit status if there are no matches or null or false is returned

[thomas-zahner]

Seems like version v0.22.0 was skipped, see this PR. So there might be a bug when retrieving the version.

[Arteiii]

Seems like version v0.22.0 was skipped, see this PR. So there might be a bug when retrieving the version.

That's normal behaviour if v0.22.0 and v0.23.0 were pushed in a short time frame, and since the workflow only runs every Sunday, it takes the latest version and opens a PR for this, not for versions that were pushed before, which shouldn't matter as there are usually not multiple major releases within a week.