If it's a fixed string, don't bother with a regex at all. Just use substr:

my $target = '[**REQUIRES USER CONTEXT**]';
my $len = length $target; # or just count it yourself ;-)
# later...
print if substr($item, -$len, $len) eq $target;
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Which depends on the fact that a negative second argument to substr counts from the end of the string.

HTH