This will do what you have requested: Connect via TCP and receive the first message sent form the server (which is the 'SSH-2.0-OpenSSH_7.4' you are after):

use IO::Socket::INET;

# Connect to TCP socket
my $socket = new IO::Socket::INET(
    PeerHost => '10.0.0.1',
    PeerPort => '1234',
    Proto => 'tcp',
    Timeout => 3
);

if ($socket)
{
    # We are connected...
    my $buffer = "";
    my $length = 1024;
    $socket->recv($buffer, $length);    
    $socket->close();
    print "OK - got message '$buffer'";
}
else
{
    # Connection failed
    print "Failed";
}
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