Fixes#40975.
8.0.32 (was running in Aurora managed cloud at the time) -> 8.0.39 (what
we're running now) 8.0.36 -> 8.0.44 (latest 8.0.x version supported by
Aurora; holding off on 8.0.45 until Aurora supports it) 8.4.7 -> 8.4.8
9.5.0 -> 9.6.0
Also bumped the supported Aurora version from 3.07.0 to 3.08.2 to match
what we're running in managed cloud right now
Fleet might work on older patch versions but we'll no longer dev/test on
them. MySQL 9.x not testing previous minor versions matches with our
previous approach for that version.
Since these are all patch/minor bumps (and the overnight build cases are
patch bumps/are covered by AWS envs) automated testing should be
sufficient here.
#15881
This PR adds a script to test DB migrations with Percona XtraDB 5.7.25.
PS: To run this test before we merge this PR to `main` you will need to
change step 2 (`Make sure to be on latest main`), instead of `main` use
this branch `15881-test-migrations-with-percona`.
