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/api/actions/actions.go

@@ -4,7 +4,6 @@
 package actions
 
 import (
-	"context"
 	"net/http"
 
 	"code.gitea.io/gitea/modules/web"
@@ -12,7 +11,7 @@ import (
 	"code.gitea.io/gitea/routers/api/actions/runner"
 )
 
-func Routes(_ context.Context, prefix string) *web.Route {
+func Routes(prefix string) *web.Route {
 	m := web.NewRoute()
 
 	path, handler := ping.NewPingServiceHandler()