Description of problem:
Package gmsh fails to build from source in Fedora Rawhide.

Version-Release number of selected component (if applicable):
4.13.2-8.fc42

Steps to Reproduce:
koji build --scratch f43 gmsh-4.13.2-8.fc42.src.rpm

Additional info:
This package is tracked by Koschei. See:
https://koschei.fedoraproject.org/package/gmsh


In file included from /builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/contrib/hxt/core/include/hxt_omp.h:4,
                 from /builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:28:
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:448:1: error: template with C linkage
  448 | template<typename __T, omp_allocator_handle_t __Handle>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:475:1: error: template with C linkage
  475 | template<typename __T, typename __U, omp_allocator_handle_t __Handle>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:483:1: error: template with C linkage
  483 | template<typename __T, omp_allocator_handle_t __Handle,
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:492:1: error: template with C linkage
  492 | template<typename __T, typename __U, omp_allocator_handle_t __Handle>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:500:1: error: template with C linkage
  500 | template<typename __T, omp_allocator_handle_t __Handle,
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:511:1: error: template with C linkage
  511 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:515:1: error: template with C linkage
  515 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:519:1: error: template with C linkage
  519 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:523:1: error: template with C linkage
  523 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:527:1: error: template with C linkage
  527 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:531:1: error: template with C linkage
  531 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:535:1: error: template with C linkage
  535 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:539:1: error: template with C linkage
  539 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:543:1: error: template with C linkage
  543 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~
/usr/lib/gcc/aarch64-redhat-linux/15/include/omp.h:557:1: error: template with C linkage
  557 | template<typename __T>
      | ^~~~~~~~
/builddir/build/BUILD/gmsh-4.13.2-build/gmsh-4.13.2-source/src/mesh/meshGRegionHxt.cpp:27:1: note: ‘extern "C"’ linkage started here
   27 | extern "C" {
      | ^~~~~~~~~~