DEPS: Remove isolated client.

This is not used anymore.
Upstream: https://crrev.com/a5547854f1e8cb6bd3

Bug: angleproject:6666
Change-Id: I3c6089e0ff6b27d88ca2adaeea40f324e808de8d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3265530
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

DEPS

@@ -557,10 +557,6 @@ deps = {
         'package': 'infra/tools/luci/isolate/${{platform}}',
         'version': Var('luci_go'),
       },
-      {
-        'package': 'infra/tools/luci/isolated/${{platform}}',
-        'version': Var('luci_go'),
-      },
       {
         'package': 'infra/tools/luci/swarming/${{platform}}',
         'version': Var('luci_go'),