expect-post-runner.sh: Remove apt install command as it's already available

Was installed in docker image long ago.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: Ic83bf71bf665c13b690a6811856c791bf84f693d
(cherry picked from commit fee1ff8d678ad1a6115288b80fc24ab8e804e892)
1 file changed