tailcfg: add recorders field to SSHRule struct

This change introduces the Recorders field to the SSHRule struct. The
field is used to store and define addresses where the ssh recorder is
located.

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>

tailcfg/tailcfg_clone.go

@@ -375,6 +375,7 @@ func (src *SSHRule) Clone() *SSHRule {
 		dst.Action = new(SSHAction)
 		*dst.Action = *src.Action
 	}
+	dst.Recorders = append(src.Recorders[:0:0], src.Recorders...)
 	return dst
 }
 
@@ -384,6 +385,7 @@ var _SSHRuleCloneNeedsRegeneration = SSHRule(struct {
 	Principals  []*SSHPrincipal
 	SSHUsers    map[string]string
 	Action      *SSHAction
+	Recorders   []netip.AddrPort
 }{})
 
 // Clone makes a deep copy of SSHPrincipal.