TOOLS/PERF: Use omp masked on OpenMP 5.1 and newer (test only, drop before merge)

Temporary copy of openucx#11908 so the fedora44 rows in this PR build with GCC
16. Revert or drop this commit once openucx#11908 lands.

(cherry picked from commit 087470a)

Author: Alexey-Rivkin

src/tools/perf/perftest.c

@@ -248,7 +248,11 @@ static void sock_rte_barrier(void *rte_group, void (*progress)(void *arg),
 {
 #if _OPENMP
 #  pragma omp barrier
-#  pragma omp master
+#  if defined(_OPENMP) && (_OPENMP >= 202011)
+#    pragma omp masked
+#  else
+#    pragma omp master
+#  endif
 #endif
   {
     sock_rte_group_t *group = rte_group;
@@ -582,7 +586,11 @@ static void mpi_rte_barrier(void *rte_group, void (*progress)(void *arg),
 
 #pragma omp barrier
 
-#pragma omp master
+#if defined(_OPENMP) && (_OPENMP >= 202011)
+#  pragma omp masked
+#else
+#  pragma omp master
+#endif
   {
     /*
      * Naive non-blocking barrier implementation over send/recv, to call user