selftests: net: py: avoid all ports < 10k

When picking TCP ports to use, avoid all below 10k.
This should lower the chance of collision or running
afoul whatever random policies may be on the host.

Reviewed-by: Willem de Bruijn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/net/lib/py/utils.py

···
     """
     Get unprivileged port, for now just random, one day we may decide to check if used.
     """
-    return random.randint(1024, 65535)
+    return random.randint(10000, 65535)
 
 
 def wait_port_listen(port, proto="tcp", ns=None, host=None, sleep=0.005, deadline=5):