mysql-5.7 vulnerabilities

USN-6060-1 fixed several vulnerabilities in MySQL. This update provides
the corresponding update for Ubuntu 16.04 ESM.

Original advisory details:

Multiple security issues were discovered in MySQL and this update includes
new upstream MySQL versions to fix these issues.

MySQL has been updated to 5.7.42 in Ubuntu 16.04 ESM.

In addition to security fixes, the updated packages contain bug fixes, new
features, and possibly incompatible changes.

Please see the following for more information:

https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-42.html
https://www.oracle.com/security-alerts/cpuapr2023.html