Use -mavx2 too

Author: adamant-pwn

.verify-helper/config.toml

@@ -1,3 +1,3 @@
 [[languages.cpp.environments]]
 CXX = "g++"
-CXXFLAGS = ["-std=c++20", "-Wall", "-Wextra", "-O2", "-march=native"]
+CXXFLAGS = ["-std=c++20", "-Wall", "-Wextra", "-O2", "-march=native", "-mavx2"]