FATAL Error: Database invalidated. Failed to create checkpoint as .wal file does not exist

Java 21, Duckdb 1.2.2.0, OS: Linux Redhat 10

In my Java application, I am opening multiple connections from different threads to Duckdb in persistent mode. In the start of the application, I create a main connection, and now any subsequent connection is created using `DuckDBConnection.duplicate`.
DuckDB file is only accessed from this process.

My connection is created with property `jdbc_stream_results` set to true.

One of my update query failed with error:
```
java.sql.SQLException: FATAL Error: Failed: database has been invalidated because of a previous fatal error. The database must be restarted prior to being used again.
Original error: "Failed to create checkpoint because of error: Could not remove file "/home/ec2-user/duckdb/./duckdb.db.wal": No such file or directory"
```

Scenario:
1. DuckDb is being queried by a select query on a different table parallely.
2. Update/INSERT queries are coming. They are processed in different threads. To run a query, I create new connection (using duplicate) and run the query.

My duckdb.db file is around 160 GB.

Start by reproducing the concurrent select and update/INSERT scenario using DuckDBConnection.duplicate with jdbc_stream_results enabled, focusing on the checkpoint failure involving duckdb.db.wal. Inspect the Java JDBC connection behavior around duplicate connections and determine whether the database remains valid during concurrent access without a missing-WAL-file error.

Written by the indexing model from the issue text.