refactor: use default error response for swagger (#40048)

ref: https://github.com/go-gitea/gitea/pull/39942#discussion_r4393487959

routers/api/v1/admin/email.go

@@ -32,8 +32,8 @@ func GetAllEmails(ctx *context.APIContext) {
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/EmailList"
-	//   "403":
-	//     "$ref": "#/responses/forbidden"
+	//   default:
+	//     "$ref": "#/responses/error"
 
 	listOptions := utils.GetListOptions(ctx)
 
@@ -79,8 +79,8 @@ func SearchEmail(ctx *context.APIContext) {
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/EmailList"
-	//   "403":
-	//     "$ref": "#/responses/forbidden"
+	//   default:
+	//     "$ref": "#/responses/error"
 
 	ctx.SetPathParam("email", ctx.FormTrim("q"))
 	GetAllEmails(ctx)