Remove testing of `latest-everything` from every single PR CI run

[jfy133]

Currently every PR on an nf-core pipeline repository will run the tests on both latest stable and edge release.

However because of nf-test sharding we don't actually report a failure of latest-everything to prevent blocking of merging on the PR conversation tab which is where most people look to see their test status (polling the maintainers team, people rarely check the 'Run nf-test' summary page in the 'checks' tab).,

I suggest we remove the latest-everything runs from every PR, maybe reserving only for release PRs from dev to master, to help reduce our environmental impact.

@mirpedrol also points out we have 'nightly builds' which should help us detect if upcoming Nextflow changes will cause problems.

[awgymer]

I'd agree completely. I just started running tests in a non-nf-core pipeline and the fact that they are always green makes them effectively meaningless to me. I was wondering why "latest" tests were passing but the 25.04 ones were not, only to discover that the latest were, in fact, failing too.

I think realistically there is no nice way to run these tests and have them be both non-blocking and meaningful. The issue being that GitHub only provides pass/fail, and ideally what we really want is some kind of warning that latest tests have failed.

Perhaps a solution could be to have the tests pass but post a comment onto the PR, or find some way for them to be run on the master branch once a week (or some other appropriate window) and to have the status for the repo reported in a badge (like the overall CI status is)?