[ci] Add Ubuntu 24.04 builds (read before merging!)

[dpiparo]

This PR can be merged only when Ubu24 tests are all passing.

[github-actions[bot]]

Test Results

    12 files      12 suites   2d 20h 6m 37s :stopwatch:  2 635 tests  2 626 :white_check_mark: 0 :zzz: 9 :x: 29 925 runs  29 916 :white_check_mark: 0 :zzz: 9 :x:

For more details on these failures, see this check.

Results for commit 0600d238.

[vepadulano]

I propose we enable the Ubuntu 24 build together with the PR that fixes it https://github.com/root-project/root/pull/15415

[vepadulano]

The related PR was merged, closing this one