Bug 19169: Add a test to detect unneeded 'atomicupdate' files

to test...

1/ set git repo
    $ git reset --hard v21.11.03

2/ run test
    $ prove ./t
    OK

3/ apply patch

4/ run test again, observe FAIL

    $ prove ./t/00-check-atomic-updates.pl
    ./t/00-check-atomic-updates.pl .. 1/?
    #   Failed test 'check for unhandled atomic updates: bug_29596.pl'
    #   at ./t/00-check-atomic-updates.pl line 34.
    #                   'bug_29596.pl'
    #           matches '(?^u:.*pl$)'
    # Looks like you failed 1 test of 3.
    ./t/00-check-atomic-updates.pl .. Dubious, test returned 1 (wstat 256, 0x100)
    Failed 1/3 subtests

JD Amended patch: fix copyright year
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>

t/00-check-atomic-updates.pl

@@ -0,0 +1,37 @@
+# Copyright 2022 Mason James
+#
+# This file is part of Koha.
+#
+# Koha is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# Koha is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Koha; if not, see <http://www.gnu.org/licenses>.
+
+use Modern::Perl;
+use Test::More;
+use File::Find;
+
+my $dir = ('installer/data/mysql/atomicupdate');
+my @files;
+
+find( \&wanted, $dir );
+
+sub wanted {
+    push @files, $_;
+    return;
+}
+
+foreach my $f (@files) {
+    next if $f eq 'skeleton.pl';
+    unlike( $f, qr/.*pl$/, "check for unhandled atomic updates: $f" );
+}
+
+done_testing();