Pull request 2255: 4923 Fix tests

Updates #4923.

Squashed commit of the following:

commit 064d4aa30ba73c57a6ede8cced348fc7daf1aab8
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jul 9 20:51:41 2024 +0300

    dhcpsvc: close db

commit d08b70983de237a4a96e8a32360a8533c69d6868
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jul 9 20:37:42 2024 +0300

    dhcpsvc: fix test paths

internal/dhcpsvc/db.go

@@ -106,6 +106,9 @@ func (srv *DHCPServer) dbLoad(ctx context.Context) (err error) {
 
 		return nil
 	}
+	defer func() {
+		err = errors.WithDeferred(err, file.Close())
+	}()
 
 	dl := &dataLeases{}
 	err = json.NewDecoder(file).Decode(dl)