Update the add feelpp package PR for spack: add boost defaults, readline, python@:3.11

[bernhardkaindl]

@prudhomm @vincentchabannes, this "PR for the PR" contains the fixes that I've found so far:

• feelpp: new package spack/spack#46396 (review): Use Boost.with_default_variants
• • feelpp: new package spack/spack#46396 (review): feelpp uses distutils: Incompatible with Python@3.12:
  • TODO: Replace the use of distutils (which was removed in 3.12) with setuptools to support newer Python versions (and avoid build warnings about it too) in upstream feelpp itself.
  • feelpp: new package spack/spack#46396 (review): Add a missing dependency on readline. Maybe also needs a cmake include directories fix like for PugiXML when libreadline-devel is uninstalled from the build host.

PS, further FIXMEs before the build can be done on a freshly installed host in spack:

• You also need to fix add ${PUGIXML_INCLUDE_DIR} to target_include_directories in one of the two ways mentioned here when PugiXML is not installed on the host system: spack: Add ${PUGIXML_INCLUDE_DIR} to target_include_directories FMI4cpp#3
• Same fore fftw3: feelpp: new package spack/spack#46396
• Maybe the same for readline (in addition to the depend_on for readline)

PPS: Your last Merge branch 'develop' into 4-add-package-for-feelpp merged a two bad commit from the develop branch into your PR branch https://github.com/feelpp/spack/tree/4-add-package-for-feelpp:

These two bad commits have been reverted in develop afterwards, but your PR branch has not been updated or rebased to a newer develop that reverts those bad commits yet.

The result is that when trying to build feelpp, the spack compiler wrapper script (which are bad in this commit) are very very very very slow: A single compiler call has about one second of additional CPU time which makes all compiler probing take ages. This caused many builds in CI to take longer than 6 hours and was a cause of major failures and backlogs. Therefore, you need to urgently rebase it to a new develop branch before resuming test builds for testing your PR:

git remote add upstream https://github.com/feelpp/feelpp.git
git rebase upstream/develop

When updating your branch, DO NOT USE "Update with merge commit" but "Update with rebase".

Using rebase keeps (or brings your commits) on top of the commit tree, which is what you want to review your commits.

You may also possibly consider squashing your commits for the new recipe into one to consolidate the commits (only now, not always) as many commits accumulated in the PR branch.

[prudhomm]

@bernhardkaindl thank you so much for your input, I am looking into your contribution

[bernhardkaindl]

@prudhomm: You do not have to use Boost.with_default_variants: I now found that it is just a method to or a transition from an old generic boost. You can replace it with the parts of boost that are needed. But it's also not a problem to use it.

You can apply the changes I suggest on your own, or you can merge this PR into your PR branch - just approve it here if that's ok.

And, then, please run a git rebase develop to update your branch and the push it to the PR using git push -f