What feature or improvement would you like to see?

For the reasons discussed in #3374, we should either:

1. Don't search for drivers $ADBC_CONFIG_PATH. Instead search for drivers in $ADBC_CONFIG_PATH/Drivers

or

2. Rename the environment variable to ADBC_DRIVER_PATH so in the future it's not confused with other environment variables that we might define to store other ADBC configs.