Loop Hoisting

With the indentation fixed, it appears that this code isn't so bad
- (a lot better than some of the other code in this class)
The major error is that $dir is opened and read repeatedly
This doesn't depend in any way on $key
Code that doesn't depend on the loop variable at all is called invariant
It can often be hoisted out of the loop:

        my $dir = $build_photo_path;
        opendir(DIR, $dir) || &err("can't open : $!"); 
        @all_files = readdir(DIR);
        closedir(DIR);

        foreach $key (keys %delete_list) {
          my (@files) = ();
          &header;
          @files = grep { /$key\.*/i } @all_files;
          if ($#files > -1) {
            foreach (@files) {
              unlink("$dir/$_") || &err("can't delete $_ : $!");
            }
          }
        }