nostrdb: update to include ingester read_txn fixes

## Summary Updates the nostrdb submodule to include fixes for ingester thread crashes: - **Fix any_event overwrite bug** - Batches like `[EVENT, ADD_KEY]` no longer clear the flag, preventing NULL read_txn - **Add NULL guards** - Fail fast with clear error messages instead of crashing in LMDB - **Clear read_txn after abort** - Prevents use-after-free when dangling pointers are accessed ## Related PR - https://github.com/damus-io/nostrdb/pull/106 ## Note This PR depends on damus-io/nostrdb#106 being merged first. The submodule currently points to the PR branch commit. 🤖 Generated with [Claude Code](https://claude.com/claude-code)