Limiting PostgreSQL logging
Yes you can hide those messages in the log.

In the calling session, before running the INSERT statement, issue this statement:

SET log_min_messages TO log; 


If you want to still see the ERROR: part, and hide only the STATEMENT: part, use another parameter:

SET log_min_error_statement TO log; 


See docs.

Use only session parameters, your application must know which statements will be silenced. Technically, you could make the setting permanent (in postgresql.conf) but it's not a good idea. In some cases this will be a footgun.