Re-enable DepsCache using GOMA_DEPS_CACHE_FILE

scripts/slave/recipes/v8.expected/full_client_dart_fyi_v8_mac_release.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--spec",
       "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'v8', 'url': 'https://chromium.googlesource.com/v8/v8'}]",
       "--patch_root",
       "v8",
@@ skipping 270 matching lines @@
       "--src-dir",
       "[SLAVE_BUILD]/v8",
       "--goma-cache-dir",
       "[GOMA_CACHE]",
       "--buildbot-buildername",
       "v8-mac-release",
       "--buildbot-mastername",
       "client.dart.fyi",
       "--buildbot-slavename",
       "TestSlavename",
+      "--goma-deps-cache-file",
+      "v8_mac_release.gomadeps",
       "--compiler",
       "goma-clang",
       "--goma-jsonstatus",
       "/path/to/tmp/json",
       "--goma-service-account-json-file",
       "/creds/service_accounts/service-account-goma-client.json",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--"
     ],
@@ skipping 31 matching lines @@
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"branch\": \"4.2\", \"buildername\": \"v8-mac-release\", \"buildnumber\": 571, \"mastername\": \"client.dart.fyi\", \"parent_buildername\": null, \"recipe\": \"v8\", \"revision\": \"20123\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}"
     ],
     "name": "package build"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]