Bug 1604486 - Use sparse checkout for the macOS profile run. r=sheehan

Differential Revision: https://phabricator.services.mozilla.com/D60056

--HG--
extra : moz-landing-system : lando

taskcluster/ci/generate-profile/kind.yml

@@ -195,6 +195,7 @@ jobs:
                   path: artifacts/
         run:
             using: run-task
+            sparse-profile: profile-generate
             cwd: '{checkout}'
             command: ./taskcluster/scripts/misc/run-profileserver-macos.sh
         fetches: