Support actions and reusable workflows from private repos (#32562)

Resolve https://gitea.com/gitea/act_runner/issues/102

This PR allows administrators of a private repository to specify some
collaborative owners. The repositories of collaborative owners will be
allowed to access this repository's actions and workflows.

Settings for private repos:


![image](https://github.com/user-attachments/assets/e591c877-f94d-48fb-82f3-3b051f21557e)

---

This PR also moves "Enable Actions" setting to `Actions > General` page

<img width="960" alt="image"
src="https://github.com/user-attachments/assets/49337ec2-afb1-4a67-8516-5c9ef0ce05d4"
/>

<img width="960" alt="image"
src="https://github.com/user-attachments/assets/f58ee6d5-17f9-4180-8760-a78e859f1c37"
/>

---------

Signed-off-by: Zettat123 <zettat123@gmail.com>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>

routers/web/repo/githttp.go

@@ -191,7 +191,7 @@ func httpBase(ctx *context.Context) *serviceHandler {
 				taskID := ctx.Data["ActionsTaskID"].(int64)
 				p, err := access_model.GetActionsUserRepoPermission(ctx, repo, ctx.Doer, taskID)
 				if err != nil {
-					ctx.ServerError("GetUserRepoPermission", err)
+					ctx.ServerError("GetActionsUserRepoPermission", err)
 					return nil
 				}