No more hung rollbacks!
We are seeing too many production errors on Moonstream crawlers and API that look like this:

```
sqlalchemy.exc.PendingRollbackError: Can't reconnect until invalid transaction is rolled back. (Background on this error at: https://sqlalche.me/e/14/8s2b)
```

([SQLAlchemy documentation on error details](https://docs.sqlalchemy.org/en/14/errors.html#error-8s2b))

We should go through the code, `git grep ".commit("` and make sure that we are correctly handling exceptions and rolling back transactions *everywhere*.
diff --git a/crawlers/mooncrawl/mooncrawl/moonworm_crawler/continuous_crawler.py b/crawlers/mooncrawl/mooncrawl/moonworm_crawler/continuous_crawler.py
index fd99c93e..85eeade5 100644
--- a/crawlers/mooncrawl/mooncrawl/moonworm_crawler/continuous_crawler.py
+++ b/crawlers/mooncrawl/mooncrawl/moonworm_crawler/continuous_crawler.py
@@ -252,6 +252,7 @@ def continuous_crawler(
                 start_block = end_block + 1
                 failed_count = 0
             except Exception as e:
+                db_session.rollback()
                 logger.error(f"Internal error: {e}")
                 logger.exception(e)
                 failed_count += 1
['crawlers/mooncrawl/mooncrawl/moonworm_crawler/continuous_crawler.py']