Remove packages orphaned by FairMQ change

[TimoWilken]

This removes asiofi, asio and ofi since they were only used by FairMQ prior to #4869.

This PR also cleans up some leftovers from #4869, including one now-unused variable. @ktf, There was a comment in the FairMQ recipe warning not to disable the -DBUILD_EXAMPLES, but since you changed that, can the comment go too?

In addition, port the change to FairMQ from #4860 to batch the O2 rebuild with the one from this PR and/or #4869.

[dennisklein]

There was a comment in the FairMQ recipe warning not to disable the -DBUILD_EXAMPLES, but since you changed that, can the comment go too?

Just a headsup to avoid double efforts: I will make a PR within the next days with a more general cleanup of the fairmq.sh recipe.

[TimoWilken]

Hi @dennisklein, great, thanks!

If you're already changing the FairMQ recipe, perhaps you'll also find https://github.com/TimoWilken/alidistlint useful -- we're in the process of introducing this as a code checker for alidist recipes. It finds common issues in shell scripts and alidist recipe metadata.

[dennisklein]

@TimoWilken @ktf Maybe a quick style question:

We have lots of CMake configure options of this form ${ZEROMQ_ROOT:+-DZeroMQ_ROOT=$ZEROMQ_ROOT}, do you prefer to have it explicitely written out in the cmake configure command line? alibuild started out by using capitalized $<PACKAGE>_ROOT env variables while CMake then later introduced support for case-sensitive <Package>_ROOT env and CMake variables. In principle, one could drop explicit CMake config lines in the form above since FairMQ supports the capitalized env variables set by alibuild - I would personally appreciate the reduced boilerplate, but I am not sure about your latest (de facto) policies here?

[TimoWilken]

@dennisklein, I'm not sure that "our" CMake actually uses the $<PACKAGE>_ROOT env vars by default -- at least the way I understand cmake --help-policy CMP0074 is that the env vars are ignored by default, and we don't configure the policy otherwise as far as I know.

[dennisklein]

Maybe some more details: FairMQ's CMake uses find_package2 which is implemented here: https://github.com/FairRootGroup/FairCMakeModules/blob/c64d6b486febe4555a011c636a7284267ae29297/src/modules/FairFindPackage2.cmake.in#L157-L160. As you can see, find_package2 looks up env variables of the capitalized form $<PACKAGE>_ROOT. I support this (basically since forever) exactly for alibuild which sets those capitalized env variables when running the recipes.

[TimoWilken]

Ah, fair enough! In that case, I don't mind either way. I don't know of an ALICE policy on this, I don't think it's come up before...

[TimoWilken]

Rebased and removed cleanups obsoleted by #4882. Now, this PR just removes the unused asio, asiofi and ofi recipes.