Clarify solution of lab_4.3.sql

It is not clear that step6's query is expected to fail. As we updated the question to suggest it might not work, I am updating the solutions to explicitly say that it doesn't work and why.

developer/04_inserting_data/lab_4.3.sql

@@ -39,6 +39,11 @@ SETTINGS
 format_csv_delimiter='~',
 schema_inference_hints='approved_amount UInt32, recommended_amount UInt32';
 
+/*
+ * No, the command above does not work. It fails becuase the data contains `n/a`
+ * in the `approved_amount` that cannot be parsed to UInt32.
+ */
+
 --Step 7:
 CREATE TABLE operating_budget (
     fiscal_year LowCardinality(String),
@@ -105,4 +110,4 @@ WHERE fiscal_year = '2022';
 SELECT sum(actual_amount)
 FROM operating_budget
 WHERE fiscal_year = '2022'
-AND program_code = '031';
+AND program_code = '031';