Bug 31108: rename ./t/00-check-atomic-updates.pl extension to *.t

Bug 31108: rename ./t/00-check-atomic-updates.pl extension to *.t

to test...

1/ run prove, test is not run :(
 prove ./t | grep 00-check-atomic-updates.pl | wc -l
 0

2/ apply patch

3/ run prove, test is run :)
 prove ./t | grep 00-check-atomic-updates.t | wc -l
 2

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 8884068904b77ecb8dff7875a056129443b08e6b)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>