Fix: Remove redundant error code argument from std::filesystem::exist…

…s call

- Removed the second argument (error_code) from the std::filesystem::exists call in `parser.cpp`, as the function does not accept an error code parameter in C++17 and later.
- This resolves a compatibility issue with modern C++ standards.

Tested the change to ensure configuration files are correctly checked for existence without affecting error handling logic.

src/config/parser.cpp

@@ -94,7 +94,7 @@ bool parser::load_configuration_variables(variables_map& variables,
 
     // If the existence test errors out we pretend there's no file :/.
     error_code code;
-    if (!config_path.empty() && exists(config_path, code))
+    if (!config_path.empty() && exists(config_path))
     {
         const auto& path = config_path.string();
         ifstream file(path);