Support for MySQL 8.4.2 (#21364)

#21270

The main change for MySQL 8.4.2 is that foreign key constraints are
stricter:
https://dev.mysql.com/doc/refman/8.4/en/server-system-variables.html#sysvar_restrict_fk_on_non_standard_key

Also, most replica-related commands have been renamed.

# Checklist for submitter

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [x] Added/updated tests
- [x] If database migrations are included, checked table schema to
confirm autoupdate
- [x] Manual QA for all new/changed functionality

.github/workflows/test-go.yaml

@@ -45,7 +45,7 @@ jobs:
         suite: ["integration", "core"]
         os: [ubuntu-latest]
         go-version: ['${{ vars.GO_VERSION }}']
-        mysql: ["mysql:8.0.36"]
+        mysql: ["mysql:8.0.36", "mysql:8.4.2"]
     continue-on-error: ${{ matrix.suite == 'integration' }} # Since integration tests have a higher chance of failing, often for unrelated reasons, we don't want to fail the whole job if they fail
     runs-on: ${{ matrix.os }}