Add missing 404 response to Swagger (#27038)

Most middleware throw a 404 in case something is not found e.g. a Repo
that is not existing. But most API endpoints don't include the 404
response in their documentation. This PR changes this.

routers/api/v1/repo/hook.go

@@ -50,6 +50,8 @@ func ListHooks(ctx *context.APIContext) {
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/HookList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
 
 	opts := &webhook.ListWebhookOptions{
 		ListOptions: utils.GetListOptions(ctx),
@@ -157,6 +159,8 @@ func TestHook(ctx *context.APIContext) {
 	// responses:
 	//   "204":
 	//     "$ref": "#/responses/empty"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
 
 	if ctx.Repo.Commit == nil {
 		// if repo does not have any commits, then don't send a webhook
@@ -224,6 +228,8 @@ func CreateHook(ctx *context.APIContext) {
 	// responses:
 	//   "201":
 	//     "$ref": "#/responses/Hook"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
 
 	utils.AddRepoHook(ctx, web.GetForm(ctx).(*api.CreateHookOption))
 }
@@ -259,6 +265,8 @@ func EditHook(ctx *context.APIContext) {
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/Hook"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
 	form := web.GetForm(ctx).(*api.EditHookOption)
 	hookID := ctx.ParamsInt64(":id")
 	utils.EditRepoHook(ctx, form, hookID)