When I was reviewing the remaining CDI 4.0 work, I realized we kept the session scope in CDI Lite. I believe it should be moved to CDI Full, because:

• the session scope is not actually defined at all in Core CDI
• the definition in CDI EE heavily relies on the Servlet API, which isn't even proposed to be part of the Jakarta EE 10 Core Profile (per https://eclipse-ee4j.github.io/jakartaee-platform/jakartaee10/JakartaEE10CoreProfileRelasePlan)
• modern application architectures often don't rely on in-memory HTTP sessions at all (and we've deliberately left passivation out of Lite)

Hence, I'm proposing this PR to remove the session scope from Lite. It stays in Full.