feat: added schema evolution to MERGE statement

Signed-off-by: JustinRush80 <[email protected]>

crates/core/src/operations/cast/merge_schema.rs

@@ -292,7 +292,7 @@ pub(crate) fn merge_arrow_field(
 /// Merges Arrow Table schema and Arrow Batch Schema, by allowing Large/View Types to passthrough.
 // Sometimes fields can't be merged because they are not the same types. So table has int32,
 // but batch int64. We want the preserve the table type. At later stage we will call cast_record_batch
-// which will cast the batch int64->int32. This is desired behaviour so we can have flexibility
+// which will cast the batch int64->int32. This is desired behavior so we can have flexibility
 // in the batch data types. But preserve the correct table and parquet types.
 //
 // Preserve_new_fields can also be disabled if you just want to only use the passthrough functionality