If the marker is a plain string (as in the example, without regex specials), substr and rindex ought to do the job:

my $idx = rindex($text, "Tags");
if ($idx > -1) {
  substr($text, $idx) = '';
}
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Otherwise you could for instance take advantage of * being greedy from the start:

$text =~ s/(.*)Tags.*/$1/s;
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