rust_tools: add copy_rust_bootstrap.py

SDK builder artifacts have changed, so copying them directly to
localmirror doesn't work. Add a script that gives us a similar level of
convenience.

Due to the simplicity of this script, no tests are provided.

BUG=b:237786394
TEST=Ran it to upload rust-bootstrap-1.59.0 artifacts

Change-Id: I64ff8f6e9043487b3dd5abf04e5f7cca36852f0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3764008
Commit-Queue: George Burgess <gbiv@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>
Reviewed-by: Michael Benfield <mbenfield@google.com>
1 file changed