feat(tasks) Collect metrics for all scheduled tasks (#97049)

Some tasks are only scheduled a few times per day and it can be
frustrating to debug schedules when metrics are sampled out.

Author: markstory

src/sentry/taskworker/scheduler/runner.py

@@ -244,6 +244,7 @@ def _try_spawn(self, entry: ScheduleEntry) -> None:
                     "taskname": entry.taskname,
                     "namespace": entry.namespace,
                 },
+                sample_rate=1.0,
             )
         else:
             # We were not able to set a key, load last run from storage.