This commit fixes the check by avoiding a fallback to eventType's
hasUnresolvableGenerics(). This could previously lead to checking a
generic event type `A<T>` against a listener which accepts unrelated
`B` and return `true` despite the inconsistency.
Note that this wouldn't necessarily surface to the user because there is
a `catch (ClassCastException e)` down the line, which was primarily put
in place to deal with lambda-based listeners but happens to catch an
exception thrown due to the bad result of `supportsEventType`.
The `supportsEventType` now matches generic `PayloadApplicationEvent`
types with a raw counterpart, using the above fallback only in that case
and otherwise ultimately returning `false`.
Closes gh-30399
c733ae0f22