Comment 8 for bug 1923845

@juliank Xenial's apt/python3-apt does not work even with zstd installed:

root@x-zstd:~# python3
Python 3.5.2 (default, Jan 26 2021, 13:30:48)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import apt_inst, apt_pkg
>>> apt_inst.DebFile("glibc-doc-reference_2.33-0ubuntu2~zstd1_all.deb").control.extractall()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
SystemError: E:Internal error, could not locate member control.tar.{lz4gzxzbz2lzma}
>>>
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=====================================-=======================-=======================-================================================================================
ii zstd 1.3.1+dfsg-1~ubuntu0.16 amd64 fast lossless compression algorithm -- CLI tool