dbt does not drop __dbt_backup after running full refresh mode

[vietthuan0404]

After running full refresh mode, dbt adapter does not clean the __dbt_backup table

[jaogoy]

@vietthuan0404 If you are interested, you can try to use AI agent (cursor, codex, ...) to fix it.
Looking forward to see you PR.

[vietthuan0404]

Can you check this PR, I haven't tested yet
#103

[jaogoy]

It could be better to add test cases and past the test.

cc @chris-celerdata