[fuchsia] Remove unnecessary files from test-scripts cipd

These files are not only useless, but sometimes harmful. E.g.
PRESUBMIT.py may be wrongly included.

So this change removes obvious unused files.

See
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket/8737497975710223921/+/u/building_chromium_fuchsia_test-scripts/List_files_to_be_packaged/listdir
for the updated file list.

Cq-Include-Trybots: luci.chromium.try:3pp-linux-amd64-packager
Bug: 346806334
Change-Id: I39d155127a1d034683d3d550450bc3f31eaa8d03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5842852


Commit-Queue: Zijie He <zijiehe@google.com>
Reviewed-by: Haiyang Pan <hypan@google.com>
Cr-Commit-Position: refs/heads/main@{#1353021}