[Feature] Add TRUNCATE INSERT to materializations list about dbt-redshift

[amychen1776]

@akmalsoliev Does the delete+insert method for incremental materialization fit your use case here?https://docs.getdbt.com/docs/build/incremental-strategy#supported-incremental-strategies-by-adapter

[akmalsoliev]

@amychen1776 Hello and sorry for a late reply. Using DELETE + INSERT is not ideal because it occasionally changes the predefined data type. For example, a VARCHAR(100) might unexpectedly become VARCHAR(250). This is not the desired behaviour; we want the operation to forcefully fail in such cases. I understand that this should not be happening, however, in practice this action occurred.
Additionally, DELETE + INSERT strategy is quite slow in comparison to TRUNCATE + INSERT.