libxc 5 not supported by elk 8.826

[marcindulak]

When building elk 8.8.26 on epel9
https://koji.fedoraproject.org/koji/taskinfo?taskID=101973812, the tests-libxc show an error:

cd tests-libxc; ../tests/test-mpi.sh
Running test in directory test_001...
 Failed! See test.log and output files
+---------------------------------+
| Elk code version 8.8.26 started |
+---------------------------------+
Number of MPI processes :      1
Number of OpenMP threads per MPI process :    2
Total number of threads (MPI x OpenMP) :      2
Maximum OpenMP nesting level :    4
Number of OpenMP threads at first nesting level :    2
Number of MKL threads :    2
RAM disk enabled
+-----------------------+
| Current task :      0 |
+-----------------------+
Error(xcdata_libxc): incompatible Libxc version : 05.002.002

[J. K. Dewhurst]

Hi Marcin,

Elk requires Libxc version 6.

Regards,
Kay.