Refactor web package and context package (#25298)

1. The "web" package shouldn't depends on "modules/context" package,
instead, let each "web context" register themselves to the "web"
package.
2. The old Init/Free doesn't make sense, so simplify it
* The ctx in "Init(ctx)" is never used, and shouldn't be used that way
* The "Free" is never called and shouldn't be called because the SSPI
instance is shared

---------

Co-authored-by: Giteabot <teabot@gitea.io>

routers/web/web.go

@@ -104,7 +104,7 @@ func ctxDataSet(args ...any) func(ctx *context.Context) {
 }
 
 // Routes returns all web routes
-func Routes(ctx gocontext.Context) *web.Route {
+func Routes() *web.Route {
 	routes := web.NewRoute()
 
 	routes.Head("/", misc.DummyOK) // for health check - doesn't need to be passed through gzip handler
@@ -146,13 +146,8 @@ func Routes(ctx gocontext.Context) *web.Route {
 
 	mid = append(mid, common.Sessioner(), context.Contexter())
 
-	group := buildAuthGroup()
-	if err := group.Init(ctx); err != nil {
-		log.Error("Could not initialize '%s' auth method, error: %s", group.Name(), err)
-	}
-
 	// Get user from session if logged in.
-	mid = append(mid, auth_service.Auth(group))
+	mid = append(mid, auth_service.Auth(buildAuthGroup()))
 
 	// GetHead allows a HEAD request redirect to GET if HEAD method is not defined for that route
 	mid = append(mid, middleware.GetHead)