tpl: Sync go_templates for Go 1.18

Using Go tag go1.18 4aa1efed4853ea067d665a952eee77c52faac774

Updates #9677

tpl/internal/go_templates/htmltemplate/content_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.13 && !windows
 // +build go1.13,!windows
 
 package template
@@ -15,7 +16,7 @@ import (
 )
 
 func TestTypedContent(t *testing.T) {
-	data := []interface{}{
+	data := []any{
 		`<b> "foo%" O'Reilly &bar;`,
 		htmltemplate.CSS(`a[href =~ "//example.com"]#foo`),
 		htmltemplate.HTML(`Hello, <b>World</b> &amp;tc!`),
@@ -452,7 +453,7 @@ func TestEscapingNilNonemptyInterfaces(t *testing.T) {
 
 	// A non-empty interface should print like an empty interface.
 	want := new(bytes.Buffer)
-	data := struct{ E interface{} }{}
+	data := struct{ E any }{}
 	tmpl.Execute(want, data)
 
 	if !bytes.Equal(want.Bytes(), got.Bytes()) {