Add @group #slow to a couple of migration tests

So looked at the times these tests start
CommentTypeRequirementsTest (https://git.drupalcode.org/issue/drupal-3526397/-/jobs/5572364) at 25 second
FollowUpMigrationsTest (in https://git.drupalcode.org/issue/drupal-3526397/-/jobs/5572365) at 32 second
MigrateFieldInstanceLabelDescriptionTest = 58 second
MigrateTaxonomyTermTranslationTest = 58 second

But see VersionTest is functional and not related to migration, that probably should be removed right

If you are another contributor eager to jump in, please allow the previous poster(s) at least 48 hours to respond to feedback first, so they have the opportunity to finish what they started!

I found some extra tests after starting here, but where I got to feels like the current list of ones that need tweaking. There's probably some @group #slow we can remove too but that should be its own issue. Updated the title and the issue summary.

Gotcha, thanks for updating. In that case seems fine to me.

Backported to 11.2.x to keep tests aligned and this is test-only.

Committed and pushed 211722d90c2 to 11.x and d847fe00531 to 11.2.x. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.