Improve port to platforms lacking euidaccess (Bug#35406)

* lib-src/emacsclient.c (set_local_socket):
Use faccessat with AT_EACCESS instead of using euidaccess.
* admin/merge-gnulib, lib/gnulib.mk.in, m4/gnulib-comp.m4:
Revert previous change.
1 job for master in 64 minutes and 4 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #1530
test-all

01:04:04