Bug 1653986 - Add new test metadata taskcluster searchfox task deps. r=kats

The enhancements in Bug 1653986 to display information about tests derives its
data from these 2 jobs and so it's appropriate to explicitly depend on them.

The current status of these jobs in the tree as far as I can tell is that:
- "source-test-file-metadata-test-info-all": Seems to get automatically
  triggered by someone's regularly, so it's always likely to be there for
  our searchfox cron jobs, but it's nice to not depend on that.
- "source-test-wpt-metadata-summary" : Seems to get automatically run, but
  only on commits that touch meta files change, per
  https://searchfox.org/mozilla-central/rev/cf561cece0ca9aeaf0202e68699836d957d0c670/taskcluster/ci/source-test/wpt-metadata.yml#31
  and indeed it wasn't there on today's searchfox jobs.

Differential Revision: https://phabricator.services.mozilla.com/D84933

taskcluster/taskgraph/target_tasks.py

@@ -902,7 +902,9 @@ def target_tasks_searchfox(full_task_graph, parameters, graph_config):
             'searchfox-macosx64-searchfox/debug',
             'searchfox-win64-searchfox/debug',
             'searchfox-android-armv7-searchfox/debug',
-            'source-test-file-metadata-bugzilla-components']
+            'source-test-file-metadata-bugzilla-components',
+            'source-test-file-metadata-test-info-all',
+            'source-test-wpt-metadata-summary']
 
 
 # Run Coverity Static Analysis once daily.