Upgrade mysql-connector to 8.4.0

[stvoutsin]

Jira issue description:

The mysql-connector-java version in the lsst-tap-service appears to be 8.0.13, which dates from 2018 (and is listed as having three direct vulnerabilities, but which are not that severe: CVE-2022-21363, CVE-2021-2471, CVE-2019-2692).

We should try updating to at least 8.0.33 or possibly mysql-connector-j 8.4.0, which appears to be the most recent available.

Among other things, this should enable us to use TLS 1.3, which is a recommended mitigation for having Qserv exposed to the Internet.

Jira issue: https://rubinobs.atlassian.net/browse/DM-44885