cmd/utils: add check on fd hard limit, skip test if below target (#15684)

* cmd/utils: Add check on hard limit, skip test if below target

* cmd/utils: Cross platform compatible fd limit test

* cmd/utils: Remove syscall.Rlimit in test

* cmd/utils: comment fd utility method

cmd/utils/fdlimit_windows.go

@@ -39,3 +39,9 @@ func getFdLimit() (int, error) {
 	// Please see raiseFdLimit for the reason why we use hard coded 16K as the limit
 	return 16384, nil
 }
+
+// getFdMaxLimit retrieves the maximum number of file descriptors this process is
+// allowed to request for itself.
+func getFdMaxLimit() (int, error) {
+	return getFdLimit()
+}