BUG #19423: canonicalize_path does not function correctly when processing paths that contain . and ..

The following bug has been logged on the website:

Bug reference:      19423
Logged by:          SHIQI LI
Email address:      1003931418@qq.com
PostgreSQL version: 14.22
Operating system:   linux
Description:

When the input parameter path of the function is
/tmp/root_hack4_test_tablespace/./../../test, the expected result after
processing by canonicalize_path is /test, but the actual result remains
/tmp/root_hack4_test_tablespace/./../../test.
The implementation of this function differs significantly between version
14, version 15, and later versions.