api/additionalPorts: don't create UDP rules

When providing additional ports to open on the control plane security
group, we'll only open TCP from now as it was initially documented.

Opening UDP by default might not be desired for security reasons.

Author: EmilienM

pkg/cloud/services/networking/securitygroups_rules.go

@@ -222,12 +222,6 @@ func getSGControlPlaneAdditionalPorts(ports []int) []resolvedSecurityGroupRuleSp
 			EtherType:   "IPv4",
 			Protocol:    "tcp",
 		},
-		{
-			Description: "Additional ports",
-			Direction:   "ingress",
-			EtherType:   "IPv4",
-			Protocol:    "udp",
-		},
 	}
 	for _, p := range ports {
 		r[0].PortRangeMin = p