fix: Preserve symlinks in untar. Fixes #9948

[swhite24]

Fixes #9948

Tested workflow provided in #9948 locally and observe symlinks being preserved when consuming artifact. Step output:

create-artifact

time="2022-11-02T20:10:11.208Z" level=info msg="capturing logs" argo=true
total 12
drwxrwxrwx    2 root     root          4096 Nov  2 20:10 .
drwxr-xr-x    3 root     root          4096 Nov  2 20:10 ..
-rw-rw-rw-    1 root     root             6 Nov  2 20:10 hello.txt
lrwxrwxrwx    1 root     root            16 Nov  2 20:10 link.txt -> output/hello.txt
time="2022-11-02T20:10:12.216Z" level=info msg="sub-process exited" argo=true error="<nil>"
time="2022-11-02T20:10:12.216Z" level=info msg="/app/output -> /var/run/argo/outputs/artifacts/app/output.tgz" argo=true
time="2022-11-02T20:10:12.216Z" level=info msg="Taring /app/output"
time="2022-11-02T20:10:12.216Z" level=debug msg="writing output"
time="2022-11-02T20:10:12.218Z" level=debug msg="writing output/hello.txt"
time="2022-11-02T20:10:12.218Z" level=debug msg="writing output/link.txt"
time="2022-11-02T20:10:12.218Z" level=info msg="archived 3 files/dirs in /app/output"

consume-artifact

time="2022-11-02T20:10:18.213Z" level=info msg="capturing logs" argo=true
total 12
drwx------    2 root     root          4096 Nov  2 20:10 .
drwxr-xr-x    3 root     root          4096 Nov  2 20:10 ..
-rw-rw-rw-    1 root     root             6 Nov  2 20:10 hello.txt
lrwxrwxrwx    1 root     root            16 Nov  2 20:10 link.txt -> output/hello.txt
time="2022-11-02T20:10:19.224Z" level=info msg="sub-process exited" argo=true error="<nil>"

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[terrytangyuan]

Thank you!