fix(benchmarks): use a copy of std.Math for the welder benchmarks, to avoid triggering false regressions

Author: SuperFola

tests/benchmarks/resources/parser/big.ark

@@ -51,7 +51,7 @@
         (set _index (+ 1 _index))})
     _output }))
 
-(import std.Math :min :max)  # needed for math:min, math:max
+(import some.Math :min :max)  # needed for math:min, math:max
 
 # @brief Drop the first n elements of a list
 # @param _L the list to work on