fix(reprocessing): Attempt to fix clear_expired_raw_events (#68040)

In #67947 I thought that this
was failing because we had no date index. It turns out there's a date
index in postgres that isn't listed on the model, so that wasn't the
problem.

Instead, it seems like the problem is that when we load a `RawEvent` we
fetch the `data` field on load, and we do all the calls serially.
Figuring out how to reword this model seems risky, so I'm lowing the
number of rows we fetch per query in the hopes that we actually managed
to perform some deletes.

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Author: wedamija

src/sentry/tasks/reprocessing.py

@@ -62,9 +62,9 @@ def clear_expired_raw_events():
     from sentry.models.reprocessingreport import ReprocessingReport
 
     # Max number of times to attempt to query each model
-    MAX_BATCHES_PER_MODEL = 1000
+    MAX_BATCHES_PER_MODEL = 10000
     # Number of rows to fetch/delete for each query
-    LIMIT_PER_QUERY = 1000
+    LIMIT_PER_QUERY = 100
 
     def batched_delete(model_cls, **filter):
         # Django 1.6's `Queryset.delete` runs in this order: