Double the size of the data processed by two tests

These two tests were broken by our PR, probably
due to the changes in when new layer files are cut.
Therefore, just do more writes to still create new
layer files.

test_runner/regress/test_remote_storage.py

@@ -269,7 +269,7 @@ def overwrite_data_and_wait_for_it_to_arrive_at_pageserver(data):
                 f"""
                INSERT INTO foo (id, val)
                SELECT g, '{data}'
-               FROM generate_series(1, 10000) g
+               FROM generate_series(1, 20000) g
                ON CONFLICT (id) DO UPDATE
                SET val = EXCLUDED.val
                """,
@@ -370,7 +370,7 @@ def churn_while_failpoints_active(result):
     log.info("restarting postgres to validate")
     endpoint = env.endpoints.create_start("main", tenant_id=tenant_id)
     with endpoint.cursor() as cur:
-        assert query_scalar(cur, "SELECT COUNT(*) FROM foo WHERE val = 'd'") == 10000
+        assert query_scalar(cur, "SELECT COUNT(*) FROM foo WHERE val = 'd'") == 20000
 
 
 @pytest.mark.parametrize("remote_storage_kind", [RemoteStorageKind.LOCAL_FS])
@@ -418,7 +418,7 @@ def overwrite_data_and_wait_for_it_to_arrive_at_pageserver(data):
                 f"""
                INSERT INTO foo (id, val)
                SELECT g, '{data}'
-               FROM generate_series(1, 10000) g
+               FROM generate_series(1, 20000) g
                ON CONFLICT (id) DO UPDATE
                SET val = EXCLUDED.val
                """,
@@ -509,7 +509,7 @@ def churn(data_pass1, data_pass2):
     log.info("restarting postgres to validate")
     endpoint = env.endpoints.create_start("main", tenant_id=tenant_id)
     with endpoint.cursor() as cur:
-        assert query_scalar(cur, "SELECT COUNT(*) FROM foo WHERE val = 'd'") == 10000
+        assert query_scalar(cur, "SELECT COUNT(*) FROM foo WHERE val = 'd'") == 20000
 
     # ensure that we updated the calls_started download metric
     fetch_calls_started()