Cache: fix CacheInterceptor in case of non-ArC interceptor bindings

RESTEasy Classic's MP RestClient implementation produces annotations
at runtime, so they are not created by ArC and therefore don't extend
`AbstractAnnotationLiteral`. At the same time, that implementation
produces an `ArcInvocationContext` and puts interceptor bindings
into its context map under the ArC key.

Some places may expect that an `ArcInvocationContext` would always
contain ArC-created `AbstractAnnotationLiteral` instances, but alas,
per the description above, that is not the case.

There are multiple options for fixing that collision. My preferred one
would be to get rid of `AbstractAnnotationLiteral` and treat all
annotations uniformly. That unfortunately has negative performance
implications on the `CacheInterceptor`, so is not an option yet [1].

This commit chooses another path: it modifies the only place in Quarkus
that actually depends on `AbstractAnnotationLiteral` to check whether
the `Set<AbstractAnnotationLiteral>` actually contains instances of
`AbstractAnnotationLiteral`. I hope that before more places in Quarkus
start depending on `AbstractAnnotationLiteral`, we can get rid of it.

This commit only checks the first annotation in the set, because
if the bindings come from RESTEasy Classic, then none of them are
instances of `AbstractAnnotationLiteral`, and if they come from ArC,
then all of them are instances of `AbstractAnnotationLiteral`.

[1] The performance issue (JDK-8180450) is fixed in JDK 23 and has
    not been backported to any LTS release as of this writing.

extensions/cache/runtime/src/main/java/io/quarkus/cache/runtime/CacheInterceptor.java

@@ -71,9 +71,10 @@ public CacheInterceptionContext<T> get() {
     private <T> Optional<CacheInterceptionContext<T>> getArcCacheInterceptionContext(
             InvocationContext invocationContext, Class<T> interceptorBindingClass) {
         Set<AbstractAnnotationLiteral> bindings = InterceptorBindings.getInterceptorBindingLiterals(invocationContext);
-        if (bindings == null) {
-            LOGGER.trace("Interceptor bindings not found in ArC");
-            // This should only happen when the interception is not managed by Arc.
+        if (bindings == null || bindings.isEmpty() || !(bindings.iterator().next() instanceof AbstractAnnotationLiteral)) {
+            // this should only happen when the interception is not managed by ArC
+            // a non-`AbstractAnnotationLiteral` can come from RESTEasy Classic's `QuarkusInvocationContextImpl`
+            LOGGER.trace("Interceptor bindings not found in ArC or not created by ArC");
             return Optional.empty();
         }
         List<T> interceptorBindings = new ArrayList<>();