[Instrumented libraries] Fix archive copying

The target is a directory, so copytree() is required instead of copy().
Also remove a no-longer-needed subprocess import.

Bug: 320564950
Change-Id: I17c409f89dd80cc8ffc204a7a09fd9e0cf26908f
R=dpranke
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/third_party/instrumented_libraries/+/5385097
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>
1 file changed