feat: use current connnection instead of the one in ActiveRecord::Base

[seuros]

This fix an issue with multi database setups where the uncached is not respecting the current database.

ActiveRecord::Base could not be configured or connected to another database.

TODO: test multiple database setup.

[thelowlypeon]

hi! any idea when this/5.2.0 will be released?

[seuros]

While the code is ready for release, I've identified a critical issue that needs to be addressed soon. The multiple connection functionality currently only works properly when using the same database adapter across connections.

Using different adapters simultaneously (such as MySQL and PostgreSQL) can lead to unexpected behavior.
I've build a solution that will require a significant rewrite of the connection handling. As noted in issue #103, this change will remove support for SQLite3 since it lacks native locking capabilities.

Please let me know if you're seeing any issues with the master branch, and I'll proceed with a release once I receive your feedback.

[thelowlypeon]

@seuros thanks for the details! we thought we were having an issue related to using multiple databases, but discovered we were actually just making a mistake (we were passing transaction: true when not in a transaction). we do have multiple databases, but haven't had any problems