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/cargo.tmpl

@@ -7,14 +7,12 @@
 			<label>{{ctx.Locale.Tr "packages.owner.settings.cargo.initialize.description"}}</label>
 		</div>
 		<form class="field" action="{{.Link}}/cargo/initialize" method="post">
-			{{.CsrfTokenHtml}}
 			<button class="ui primary button">{{ctx.Locale.Tr "packages.owner.settings.cargo.initialize"}}</button>
 		</form>
 		<div class="field">
 			<label>{{ctx.Locale.Tr "packages.owner.settings.cargo.rebuild.description"}}</label>
 		</div>
 		<form class="field" action="{{.Link}}/cargo/rebuild" method="post">
-			{{.CsrfTokenHtml}}
 			<button class="ui primary button">{{ctx.Locale.Tr "packages.owner.settings.cargo.rebuild"}}</button>
 		</form>
 		<div class="field">