Replace CSRF cookie with CrossOriginProtection (#36183)

Removes the CSRF cookie in favor of
[`CrossOriginProtection`](https://pkg.go.dev/net/http#CrossOriginProtection)
which relies purely on HTTP headers.

Fixes: https://github.com/go-gitea/gitea/issues/11188
Fixes: https://github.com/go-gitea/gitea/issues/30333
Helps: https://github.com/go-gitea/gitea/issues/35107

TODOs:

- [x] Fix tests
- [ ] Ideally add tests to validates the protection

---------

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/package/shared/cleanup_rules/edit.tmpl

@@ -1,7 +1,6 @@
 <h4 class="ui top attached header">{{if .IsEditRule}}{{ctx.Locale.Tr "packages.owner.settings.cleanuprules.edit"}}{{else}}{{ctx.Locale.Tr "packages.owner.settings.cleanuprules.add"}}{{end}}</h4>
 <div class="ui attached segment">
 	<form class="ui form" action="{{.Link}}" method="post">
-		{{.CsrfTokenHtml}}
 		<input name="id" type="hidden" value="{{.CleanupRule.ID}}">
 		<div class="field">
 			<div class="ui checkbox">