[cmake] fixes for cmake 4.0.0

[couet]

cmake 4.0.0 (the official current cmake version) needs some fixes for DAVIX VDT etc ..(see #18312)

[guitargeek]

The Fedora 42 build config has disable some builtins and features because of CMake 4:
https://github.com/root-project/root/blob/master/.github/workflows/root-ci-config/buildconfig/fedora42.txt#L9
Namely:

builtin_cppzmq=OFF
builtin_zeromq=OFF
roofit_multiprocess=OFF

Can we remove these lines in the same PR maybe? That would also ensure your changes get more test coverage. But can also be done later

[github-actions]

Test Results

    18 files      18 suites   4d 6h 19m 30s ⏱️
 2 722 tests  2 721 ✅ 0 💤 1 ❌
47 315 runs  47 314 ✅ 0 💤 1 ❌

For more details on these failures, see this check.

Results for commit 36f1fdc.

♻️ This comment has been updated with latest results.

[dpiparo]

@couet when it's time to merge can you please reformulate the commit messages?

[dpiparo]

The commit messages need a bit of attention: see https://github.com/root-project/root/blob/master/CONTRIBUTING.md .
For example, the commit messages start with a tag. For example, the commit in the fedora42 configuration should start with "[ci]" while the one for the CMakeLists with "[cmake]". Moreover, the commit message should describe the why of the changes, rather than the what and how - we can gather this from the commit summary and the change diff, respectively. The commit message should be wrapped at 72 characters.

[couet]

I do not see how to modify the message for fedora42 I guess at merging time it will be possible ?

[ferdymercury]

I do not see how to modify the message for fedora42 I guess at merging time it will be possible ?

Locally it's possible:

git checkout cmake-fix
git rebase --interactive master
# replace by hand "pick" with "reword". Save and Exit.
# edit and save message commit by commit.
git push -f origin cmake-fix

(Sometimes, it takes less time to just open a new PR from scratch with completely new commits.)