• Fixes an issue where during the evaluation of workspaces for dormancy, an attempt was made to insert an audit log in the midst of a transaction. If a sufficiently large number of workspaces were found eligible for dormancy a deadlock could occur where each transaction would attempt to write an audit log outside the transaction, consuming a DB connection. We limit the number of concurrent transactions in autobuild to 10 so 10 connections could potentially be consumed leaving none free to handle the audit logging, effectively deadlocking the DB.
• We also now return errors from the transaction where it makes sense. I can't tell if it was a conscious decision to always return nil or not. Perhaps because it's mostly a read transaction it's less expensive to commit instead of rollback?
• The feature has not been released so this does not effect production deployments.

The solution is obviously to not do non-transaction DB operations from within a transaction. This was not an intentional implementation decision.

We could potentially add a timeout to the context we use in the transactions we open in autobuild but if a similar bug were to occur it would just provide temporary relief.

I'm a bit hesitant on adding the test for this since it's sort of easy for it to produce a false-positive. If we want to retain it I'll rewrite it to use our new dbfake implementation.

fixes https://github.com/coder/customers/issues/314