online: Disable parallel sorting to prevent memleak from libTBB

Refs #3028

algo/base/compat/Algorithm.h

@@ -19,8 +19,7 @@
 
 #include <algorithm>
 
-#if defined(__cpp_lib_execution) && defined(HAVE_PARALLEL_ALGORITHM)
-#define WITH_EXECUTION
+#ifdef HAVE_PARALLEL_ALGORITHM
 #include <execution>
 #endif
 
@@ -36,7 +35,11 @@ namespace cbm::algo
   template<typename It, typename Compare>
   void Sort(It first, It last, Compare comp)
   {
-#ifdef WITH_EXECUTION
+// Disable parallel sorting for the moment
+// The underlying implementation in libTBB has a massive memory leak:
+// https://community.intel.com/t5/Intel-oneAPI-Threading-Building/std-sort-std-execution-par-unseq-has-a-memory-leak-on-Linux/m-p/1580910
+#if 0
+// #ifdef HAVE_PARALLEL_ALGORITHM
     std::sort(std::execution::par_unseq, first, last, comp);
 #else
     std::sort(first, last, comp);