bug: builtin modpath() returns a wrong path

[zong-zhe]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. create a init kcl module

kcl mod init demo

2. change the main.k in demo

The main.k

import file

a = file.modpath()

3. run the demo

kcl run demo

2. What did you expect to see? (Required)

a: '<the path of the demo>'

3. What did you see instead (Required)

The result is empty

a: ''

4. What is your KCL components version? (Required)

The main branch