Drop artifacts that support disabling shadow headers

Releasing SHA: https://team.git.corp.google.com/foundry-x/re-client/+/ffdcda06c0512dd240d168f1e8c8de3bcbe80a80

Test: The following.
kousikk@altonimbus:~/foundry-x/internal-master-2/prebuilts/remoteexecution-client$ ./test-disable-shadow-headers/rewrapper --version
Version: 0.5.3.ffdcda0
kousikk@altonimbus:~/foundry-x/internal-master-2/prebuilts/remoteexecution-client$ ./test-disable-shadow-headers/reproxy --version
Version: 0.5.3.ffdcda0
kousikk@altonimbus:~/foundry-x/internal-master-2/prebuilts/remoteexecution-client$ ./test-disable-shadow-headers/bootstrap --version
Version: 0.5.3.ffdcda0
kousikk@altonimbus:~/foundry-x/internal-master-2/prebuilts/remoteexecution-client$ ./test-disable-shadow-headers/dumpstats --version
Version: 0.5.3.ffdcda0

Change-Id: I43b39e8c47eaf426a87c70b2cc3e10c391660557