Login With Public Key timeouts when opening more that 3 different connections

Hi,

- robotframework 6.0.1
- python 3.11
- robotframework-sshlibrary 3.8.0
- linux

I am trying to setup my test suite to test 16 similar devices using SSH. But I get an error when trying to open the 4 connection: `TimeoutError: timed out`

Here is the an example of my code.
```
*** Settings ***
Documentation Demo

Library SSHLibrary
Suite Setup Open All Connections ${devices}
Suite Teardown Close All Connections

*** Keywords ***
Open Connection And Log In
[Arguments] ${HOST} ${ALIAS}
Open Connection ${HOST} alias=${ALIAS}
Login With Public Key ${USERNAME} ${ssh_keyfile}

Open All Connections
[Arguments] ${TESTS}
FOR ${test} IN @{TESTS}
Open Connection And Log In ${test}[host] ${test}[id]
END
```

Detailed error for the robotframework log:
```
# ERROR
SSHLibrary . Login With Public Key ${USERNAME}, ${ssh_keyfile}
Documentation:
Logs into the SSH server using key-based authentication.

Start / End / Elapsed: 20221124 16:06:51.363 / 20221124 16:06:54.372 / 00:00:03.009
16:06:51.363 INFO Logging into '192.168.2.205:22' as 'test'.
16:06:54.367 FAIL TimeoutError: timed out
```

- I tried to change the order of the devices but it's still timeouts.
- I tried changing the default timeout `Set Default Configuration timeout=5 minutes` but it hangs also and it just takes longer to timeout. it's always the connection number 4 that fails.

I changed the code to open and close every connection directly in the test case:
```
Verify Demo
FOR ${test} IN @{TEST}
Open Connection And Log In ${test}[host] ${test}[id]
Verify Demo
Close Connection
END
```
Still fails at the 4 connection.

However there is no issue if I try to open 6 times the same IP.

Thanks for your help.

Start with the reported Robot Framework flow in `Open Connection And Log In`, especially `Open Connection` followed by `Login With Public Key`, and reproduce it with four different device IPs. Compare it with opening six connections to the same IP; done means the fourth distinct connection no longer times out, or the limitation and required configuration are documented.

Written by the indexing model from the issue text.