Related issue: #1493

Description

MySQL 8.4 deprecates several old-style master/slave commands. Unfortunately, we had upgraded our DB to 8.4.3 and then found out after the fact that gh-ost broke, so this PR aims to introduce compatibility across 8.4+.

In case this PR introduced Go code changes:

• contributed code is using same conventions as original code
• script/cibuild returns with no formatting errors, build errors or unit test errors.

I wasn't able to get a minimal mysql 8.4 tarball that would actually pass the CI tests with dbdeployer but did manage to get the docker version running and passing: https://github.com/chen-anders/gh-ost/actions/runs/13026574857