CompatHelper: bump compat for LightSumTypes to 5, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the LightSumTypes package from 4 to 4, 5.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[Datseris]

@Tortar I would recommend to attribute more weight on breaking releases, or to take them a bit more seriously. This rate of breaking releases is rather alarming and if I was a direct user I would really be concerned. Especially given that there is no CHANGELOG at the repo.

It really is worth considering whether that many breaking releases are necessary, especially given that the package has users now (not only us, you saw the interest in discourse was clear). In particular this latest v5 could have been justified more, as looking at the changes it could have just been made a documentation PR: things that aren't documented, it doesn't matter much if they are still there or not.

[Tortar]

yes, George you are right, but I have explicitly wrote in the commits that it is only about removing deprecated functionalities (deprecated nearly 3 months ago), so it should be fine in this case in my opinion.

But this particular PR should be merged when we release Agents 6.2 because we have guaranteed that the old deprecated multiagent stuff would have worked until that point in the past, if I recall correctly

[Tortar]

I think deprecation removal should always require a new release if not stated otherwise (yes I could have stated otherwise in the deprecations probably, my bad)

[Datseris]

yes, George you are right, but I have explicitly wrote in the commits that it is only about removing deprecated functionalities (deprecated nearly 3 months ago), so it should be fine in this case in my opinion.

Keep in mind that this ignores that simply having to check whether the breaking changes affect you or not as a user is already a downside. So breaking changes come at a burden to your users even if they don't affect them. Well, some users never check versions at all so these don't count.