`stat` only provide timestamp down to second instead of nanosecond

[kocoten1992]

Description

Hi maintainer,

stat in php only provide presicion down to second, but it could be down to nanosecond.

  File: abc.xyz
  Size: 0         	Blocks: 0          IO Block: 4096   regular empty file
Device: 8,2	Inode: 6160531     Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 0/root)   Gid: ( 0/root)
Access: 2023-08-12 09:10:14.152726478 +0700
Modify: 2023-08-12 09:10:14.152726478 +0700
Change: 2023-08-12 09:10:14.152726478 +0700
 Birth: 2023-08-12 09:10:14.152726478 +0700

[
  ...,
  "atime" => 1691806214,
  "mtime" => 1691806214,
  "ctime" => 1691806214,
  ...
]

I'm aware that https://linux.die.net/man/2/stat does explain it Since kernel 2.5.48, the stat structure supports nanosecond resolution for the three file timestamp fields..

I was running into this problem today, run test need to ensure directory was created within 1s, which cannot be done if read from php stat.

[kocoten1992]

It pretty troublesome, I think DateTime object also do not support nanosecond (I've create an issue for it here #11949).