Fix swagger title (#28164)

![image](https://github.com/go-gitea/gitea/assets/18380374/380859b2-a643-42fd-b53e-78c93c05c826)
Don't know why there's a `.` behind. 🤔

Author: yp05327

routers/api/v1/api.go

@@ -2,7 +2,7 @@
 // Copyright 2016 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
-// Package v1 Gitea API.
+// Package v1 Gitea API
 //
 // This documentation describes the Gitea API.
 //