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/api/v1/user/user.go

@@ -77,7 +77,7 @@ func Search(ctx *context.APIContext) {
 			Actor:         ctx.Doer,
 			Keyword:       ctx.FormTrim("q"),
 			UID:           uid,
-			Type:          user_model.UserTypeIndividual,
+			Types:         []user_model.UserType{user_model.UserTypeIndividual},
 			SearchByEmail: true,
 			Visible:       visible,
 			ListOptions:   listOptions,