use std::filesystem::current_path in job_info (#2805)

this eliminates a C routine with a buffer

Co-authored-by: Eric T. Johnson <[email protected]>

Source/driver/Castro_io.cpp

@@ -7,6 +7,7 @@
 #include <iostream>
 #include <string>
 #include <ctime>
+#include <filesystem>
 
 #include <AMReX_Utility.H>
 #include <Castro.H>
@@ -578,10 +579,7 @@ Castro::writeJobInfo (const std::string& dir, const Real io_time)
   jobInfoFile << "output date / time: "
               << std::put_time(std::localtime(&now), "%c\n") << "\n";
 
-  char currentDir[FILENAME_MAX];
-  if (getcwd(currentDir, FILENAME_MAX) != nullptr) {
-    jobInfoFile << "output dir:         " << currentDir << "\n";
-  }
+  jobInfoFile << "output dir:         " << std::filesystem::current_path() << "\n";
 
   jobInfoFile << "I/O time (s):       " << io_time << "\n";