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/org/team/repositories.tmpl

@@ -11,7 +11,6 @@
 				{{if $canAddRemove}}
 					<div class="ui top attached segment tw-flex tw-flex-wrap tw-gap-2">
 						<form class="ui form ignore-dirty tw-flex-1 tw-flex" action="{{$.OrgLink}}/teams/{{$.Team.LowerName | PathEscape}}/action/repo/add" method="post">
-							{{.CsrfTokenHtml}}
 							<div data-global-init="initSearchRepoBox" data-uid="{{.Org.ID}}" class="ui search">
 								<div class="ui input">
 									<input class="prompt" name="repo_name" placeholder="{{ctx.Locale.Tr "search.repo_kind"}}" autocomplete="off" required>
@@ -40,7 +39,6 @@
 								<div class="flex-item-trailing">
 									{{if $canAddRemove}}
 										<form method="post" action="{{$.OrgLink}}/teams/{{$.Team.LowerName | PathEscape}}/action/repo/remove">
-											{{$.CsrfTokenHtml}}
 											<button type="submit" class="ui red small button" name="repoid" value="{{.ID}}">{{ctx.Locale.Tr "remove"}}</button>
 										</form>
 									{{end}}