types/ptr: deprecate ptr.To, use Go 1.26 new

Updates #18682

Change-Id: I62f6aa0de2a15ef8c1435032c6aa74a181c25f8f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ssh/tailssh/tailssh_test.go

@@ -51,7 +51,6 @@ import (
 	"tailscale.com/types/key"
 	"tailscale.com/types/logid"
 	"tailscale.com/types/netmap"
-	"tailscale.com/types/ptr"
 	"tailscale.com/util/cibuild"
 	"tailscale.com/util/lineiter"
 	"tailscale.com/util/must"
@@ -96,7 +95,7 @@ func TestMatchRule(t *testing.T) {
 			name: "expired",
 			rule: &tailcfg.SSHRule{
 				Action:      someAction,
-				RuleExpires: ptr.To(time.Unix(100, 0)),
+				RuleExpires: new(time.Unix(100, 0)),
 			},
 			ci:      &sshConnInfo{},
 			wantErr: errRuleExpired,