Verify TarWriter.TarEntry(fileName, entryName) behavior if user owner and device numbers cannot be retrieved

[carlossanlop]

We fixed #81070 which was an issue in TarWriter.WriteEntry(string fileName, string entryName) where the method would crash if we attempted to add a file to an archive whose group owner name did not exist in the platform. This is the line that we fixed: TarWriter.Unix.cs#L85

Need to verify these two other locations:

• What if the user owner gets deleted from the system?: TarWriter.Unix.cs#L76. I don't know if Unix systems would change the user owner of files if that user gets deleted. Need to test it.

  • Edit: The behavior is OK, I added tests to verify it: Add tar tests to confirm entries owned by deleted users can still be read or written #83126 and [7.0] Add tar tests to confirm entries owned by deleted users can still be read or written. #83267

• What if we have a problem retrieving device major and minor?: TarWriter.Unix.cs#L58. This case is probably fine to let it crash. If we are trying to add a block device or a character device, and we cannot retrieve its two essential numbers (device minor and minor), then it's probably ok to continue crashing.

The other two places in that same method that are ok to crash if they fail is when we do the lstat and when we create the FileStream for a regular file.

cc @jeffhandley

[carlossanlop]

Item no. 1 has been verified by adding tests: #83126 and #83267

[ViktorHofer]

According to the second point, if a crash occurs during retrieving the device major and minor then we can revisit issue.