Inherit enclosing @Conditional on scan-discovered nested configs

[Dennis-Mircea]

ISSUE link: #36820

Summary

ConfigurationClassParser and ConfigurationClassBeanDefinitionReader already inherit a nested @Configuration class's enclosing-class @Conditional annotations via the importedBy chain, but only when the inner is reached through processMemberClasses or @Import. Inners discovered via @ComponentScan or direct register(...) have no importedBy reference and silently escape the inheritance.

This PR extends both inheritance points to also walk the lexical enclosing chain (via MetadataReaderFactory) when configClass.isImported() is false. @Import semantics are intentionally preserved.

Full context, use case, prior-art relation to Spring Boot #37111, and design rationale are in the linked issue.

Test plan

• ./gradlew check on the full Spring Framework tree, all green
• :spring-context:test --tests "*Aot*", :spring-test:test --tests "*Aot*", :spring-beans:test --tests "*Aot*", all green
• Spring Boot test suite against 7.0.8-SNAPSHOT Framework with this patch published to ~/.m2/repository, all green (~10 min)
• Seven new tests in EnclosingConditionConfigurationTests pass with the patch and fail (6/7) without it; the 7th is the control case