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

Updates #18682

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

types/ptr/ptr.go

@@ -2,9 +2,18 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 // Package ptr contains the ptr.To function.
+//
+// Deprecated: Use Go 1.26's new(value) expression instead.
+// See https://go.dev/doc/go1.26#language.
 package ptr
 
 // To returns a pointer to a shallow copy of v.
+//
+// Deprecated: Use Go 1.26's new(value) expression instead.
+// For example, ptr.To(42) can be written as new(42).
+// See https://go.dev/doc/go1.26#language.
+//
+//go:fix inline
 func To[T any](v T) *T {
-	return &v
+	return new(v)
 }