Replace last use of std::uniform_int_distribution with our own

Our implementation should be slightly faster, and has the
advantage of being consistent between platforms. This does not
have immediate user impact, because we currently use random_device
to generate random seed for resampling, but if we decide to change
this in the future, it is one less place to fix.

src/catch2/benchmark/detail/catch_stats.cpp

@@ -38,7 +38,7 @@ namespace Catch {
                           double const* last,
                           Estimator& estimator ) {
                     auto n = static_cast<size_t>( last - first );
-                    std::uniform_int_distribution<size_t> dist( 0, n - 1 );
+                    Catch::uniform_integer_distribution<size_t> dist( 0, n - 1 );
 
                     sample out;
                     out.reserve( resamples );