fix: add missing cstdlib header in cli_args.cpp (#8089)

Add missing #include <cstdlib> header to provide declaration for std::strtol function used on line 67. This fixes compilation issues in some environments where the function declaration was not available.

This closes #8088

Author: karan-singare

src/realm/util/cli_args.cpp

@@ -1,6 +1,7 @@
 #include "realm/util/cli_args.hpp"
 
 #include <algorithm>
+#include <cstdlib>
 #include <cerrno>
 #include <cstdint>
 #include <string>