After updating Discourse, the following error appears in the dashboard in Top Referred Topics section:
Sorry, an error occurred while executing the query
The error is also explained in the log as follows:
Error while computing report top_referred_topics: PG::ReadOnlySqlTransaction: ERROR: cannot execute UPDATE in a read-only transaction /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-pro