embed: embed.file.ModTime() returns zero time

[yffrankwang]

The current implementation of embed.file just returns zero time.

func (f *file) ModTime() time.Time         { return time.Time{} }

The http file server does not set the http header 'Date', if file's ModTime is zero.

http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(content))))

Is it possible to set the local file's real modification time to the embed file at compile time?

[zikaeroh]

See #44854 (comment).

[seankhliao]

Duplicate of #44854