Clarify the reason for changing the storage of the Number Contract using the query function, which is readOnly permission

[Kynea0b]

The purpose of calling the function that changes storage from the query function is to detect errors in the integration test.
The relevant lines are:
https://github.com/Finschia/cosmwasm/blob/dynamic_link/contracts/call-number/src/contract.rs#L224-L226