chore: import upstream snapshot with attribution

nftables/delete_set.cgi

@@ -0,0 +1,30 @@
+#!/usr/bin/perl
+# delete_set.cgi
+# Delete an existing nftables set
+
+require './nftables-lib.pl';    ## no critic
+use strict;
+use warnings;
+our (%in, %text);
+ReadParse();
+error_setup($text{'delete_set_err'});
+assert_acl('delete');
+
+my @tables = get_nftables_save();
+my $table = $tables[$in{'table'}];
+$table || error($text{'set_notable'});
+assert_table_acl($table);
+
+my $set = $table->{'sets'}->{$in{'set'}};
+$set || error($text{'set_noset'});
+
+my $refs = count_set_references($table, $in{'set'});
+$refs && error(text('delete_set_inuse', $in{'set'}, $refs));
+
+delete($table->{'sets'}->{$in{'set'}});
+
+my $err = save_table_configuration($table, @tables);
+error(text('delete_set_failed', $err)) if ($err);
+webmin_log("delete", "set", $in{'set'},
+	{'table' => $table->{'name'}, 'family' => $table->{'family'}});
+redirect("index.cgi?table=$in{'table'}&view=sets");