The feature of golang having source in a project path with "internal"
makes the code only able to be imported by the project itself.
https://docs.google.com/document/d/1e8kOo3r51b2BWtTs_1uADIA5djfXhPT36s6eHVRIvaU/edit?tab=t.0
Since we have this carried version of `archive/tar` with our byte
accounting patches, it is also means the version of archive/tar has not
kept up with upstream.
our tar-split libraries do not even utilize all the function calls of
our carried archive/tar, so might as well limit anyone else in the world
from calling them as well.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>