QueryTranslationVariantTests: a decimal OrderBy case failed once with 'database is locked' on a private in-memory SQLite connection #147

Problem

QueryTranslationVariantTests.A_query_over_a_value_object_answers_as_the_same_query_over_the_wrapped_type(kind: "decimal", conversion: TypeKit, site: Nullable, accessor: Itself, op: OrderBy) failed once on the Linux test leg, and passed on Windows in the same run and on every earlier run:

refused where the same query over the wrapped type answers [<null>, 1.5, 10.0]: Microsoft.Data.Sqlite.SqliteException (0x80004005): SQLite Error 5: 'database is locked

Run: https://github.com/CaffeinatedCoder/CodoMetis.TypeKit/actions/runs/40889709782 (PR #141, head 5a22140, whose diff touches no EF Core code or test).

Each case seeds its own Data Source=:memory: connection (QueryTranslationVariantTests.Seeded), so no other test shares the database. A lock there points to two commands on one connection at once, such as a reader the case left open while the next command ran, rather than to contention between tests. The variant oracle then reads the lock as the value object's query being refused, so a flake reports as a translation difference.

Change

Find which command holds the lock (likely a reader from the wrapped-type side not disposed before the value-object side runs, or the seeding context still open), dispose it, and make an infrastructure exception such as SqliteException with SQLITE_BUSY/LOCKED fail the case as an error of the harness rather than as a refusal.

Done when

The case runs reliably, and an SqliteException from the harness never reads as a refusal in the oracle's message.