Remove deprecated and empty FinalizeClassesWithoutChildrenRector + FinalizePublicClassConstantRector

[TomasVotruba]

These 2 classes are empty and actually throw warning errors since 0.19.* release.
After couple of months, it's time for cleanup 👍

[laoneo]

Should this not be done in a major release as it is a breaking change? Was surprised, that my script did throw an error when I did a patch update from 1.1.0 to 1.1.1.

[TomasVotruba]

This was deprecated before 1.0, so it stayed longer than needed. It also didn't change any code and was empty to avoid causing bugs. The problem is that Rector didn't have any deprecation reporting during its run. There are couple deprecated rules now, but you would only notice them once removed. This will be fixed in next release: #6047

If you look for a replacement, see this tool that is safe and takes also Doctrine mappings into an account: https://tomasvotruba.com/blog/finalize-classes-automated-and-safe

[laoneo]

I still think that this should not be removed in a patch release if rector follows semver, even when the file got deprecated in a 0.x release. Anyway, the deprecation warning feature is nice as I was not aware of the deprecation of the file. Thanks for this.