Exclude swap files (.swp) from containment statements

https://fileinfo.com/extension/swp

.swp file is created when a text editor like nano or vim opens a file in a directory. When the editor is closed, the swap file is removed.

While swap files exist in a directory, NSS includes them in containment statements.

My attempts to GET the .swp file resulted in a 404, but this could still be a potential risk. At the very least, it does expose information when it really shouldn't.

I suggest excluding .swp from containment statements.

该 issue 提到了 containment statements 和 .swp 文件，但没有指出实现文件或测试。首先定位生成 containment statements 的代码，并使用临时 .swp 文件复现该行为。当 .swp 文件被排除在 containment statements 之外，且不会破坏其他文件的处理，同时相关测试通过时，即表示完成。