manifest: Remove flimflam from new chroots

This source code is not used or depended on anymore, and we can save
some repository space by not forcing people to pull it down.

TEST=Ran successfully:
cbuildbot --branch master --remote -g '50373' amd64-generic-paladin

BUG=chromium:221251

Change-Id: I65ea55f4f31032198c1e7cc20cc2e0e066bce68c
Reviewed-on: https://gerrit.chromium.org/gerrit/50373
Commit-Queue: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Tested-by: Christopher Wiley <wiley@chromium.org>
1 file changed