I'm able to interpolate the LIMIT parameter if I explicitly set its type to integer:

use DBI ':sql_types';
...
my $sql = q[ SELECT * FROM test.t1 LIMIT ? ];
my $sth = $dbh->prepare($sql);
$sth->bind_param(1, 10, SQL_INTEGER);  # limit=10
$sth->execute() || die $sth->errstr;
while (my @row = $sth->fetchrow_array) {
    print "row: @row\n";
}
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