ArC - detect uses of @ConversationScoped and fail the build

[manovotn]

ArC does not support @ConversationScoped but we could detect it and fail the build.
ATM we don't recognize this scope at all meaning some beans will instead end up with @Dependent scope - which is an error we could tell the user about.

To do this, we'll probably need to register conversation scope as a built-in scope and then change ContextNotActive exception to specifically mention this scope is not supported.

This issue is a follow-up to #45383

[quarkus-bot]

/cc @Ladicek (arc), @mkouba (arc)

[Ladicek]

Alternatively, we could scan the bean archive index for the @ConversationScoped annotation and if present, fail the build. (That technically wouldn't even require making ArC know about @ConversationScoped, because other scopes are virtually always guaranteed to be used.)

[manovotn]

Alternatively, we could scan the bean archive index for the @ConversationScoped annotation and if present, fail the build. (That technically wouldn't even require making ArC know about @ConversationScoped, because other scopes are virtually always guaranteed to be used.)

True, although that would prevent users from implementing their own custom conversation context.
I know it's super unlikely though ;-)