This commit aligns `SpringBootTest`s to also use `ApplicationEnvironment`
instead of `StandardEnvironment`. This prevents the side-effect of active
profiles from `@ActiveProfiles` from being added to the environment when
doGetActiveProfiles is called. In this case, calling `addActiveProfiles()`
in the environment post processor would result in `@ActiveProfiles` being
added to the environment first, resulting in the wrong order.
The additional call to `setActiveProfiles()` is also not necessary when using
ApplicationEnvironment because that call was put in place to prevent the side-effect
which `ApplicationEnvironment` does not have.
Fixes gh-28530
64270eca51