This is pretty much a brute force approach of enabling everything we had in 21.2 just to see what actually compiles. Though compiling is of course very different from actually working and being correct. Still it ought to give at least some overview of where we stand, and what definitely still needs work. I left all the packages in that did not compile, just commented out or excluded with lines in the beginning. I didn't include SUSYTools and AnalysisTop, if the decision is to keep them for run 3, I leave it to the framework maintainers to include them.
I didn't try to fix up any packages, except for one interface package that was very straightforward to make compile. The rest of the packages will not necessarily have to be fixed up one at a time, but they will at least require sitting down, taking a closer look and deciding how to fix them up.
I did manage to compile all packages locally, but didn't try running any of the tests, so let's see how things go in CI.