defaults: add 'Host datapath not ready' to expected drop reasons

This excludes the drop reason introduced in cilium/cilium#29482.
It occurs when Cilium is first installed on a node, the host firewall is
enabled, a workload endpoint gets created before the host endpoint, and the
workload endpoint in question tries to talk to the host.

Preventing these drops would require redesigning parts of the datapath,
particularly the clustermesh bootstrap procedure. This is not feasible
at the moment, and maybe it's not the right thing to do.

Signed-off-by: Timo Beckers <[email protected]>

defaults/defaults.go

@@ -202,6 +202,7 @@ var (
 		"Invalid source ip",
 		"Unknown L3 target address",
 		"No tunnel/encapsulation endpoint (datapath BUG!)",
+		"Host datapath not ready",
 	}
 
 	ExpectedXFRMErrors = []string{