fix: Disable shared cache on SQLITE, reduces SQLITE locking errors.

[omgbeez]

Per documentation by Sqlite and MS, using Cache=Shared is discouraged, especially in combination with WAL. WAL mode is supposed to be the better solution overall, and enabling shared cache changes table locking behaviour increasing errors seen from concurrent actions.

Microsoft.Data.Sqlite connection strings
Relevant sections:

Cache: Shared means connections share a cache and “can change the behavior of transaction and table locking.”
Example warning: Microsoft says mixing shared-cache mode and WAL is discouraged, and for optimal WAL performance you should remove Cache=Shared.

SQLite shared-cache mode
Relevant sections:

“Use of shared-cache is discouraged”
“Most use cases for shared-cache are better served by WAL mode”

Reading a bit on this, the only real clear use-case for Cache=Shared is when using in memory tables across multiple connections, as Cache=Private would result in multiple tables in that case (one per connection).