fix include in argparse, update cmake version

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.5)
 project(BLT VERSION 0.8.0)
 
 set(CMAKE_CXX_STANDARD 20)

include/blt/parse/argparse.h

@@ -26,7 +26,7 @@ using HASHSET = phmap::flat_hash_set<K>();
     #else
         #define HASHMAP HASHMAP
         #include <unordered_map>
-        #include <set>
+        #include <unordered_set>
 
 template<typename K, typename V>
 using HASHMAP = std::unordered_map<K, V>();