Add tar file with files starting with ./, including the current folder entry

[carlossanlop]

Addresses: dotnet/runtime#70516

The archive was generated in a Macbook Pro with the command:

tar -cvf prefixDotSlashAndCurrentFolderEntry.tar ./

• The "./" argument indicates that all the files in the current folder (including the current folder itself, but excluding the tar archive being created with this command) are to be included in the archive.
• The format is 'ustar'. For this particular bug, the format does not really matter.

The archive contains 4 entries:

./
./file.txt
./directory/
./directory/file.txt

[carlossanlop]

@ViktorHofer no need to bump the version myself, correct? I ask because such instructions are not indicated in the repo readme.