Ignore /spring-core/graalvm/build artifacts from the main branch
Ignore /spring-core/graalvm/build artifacts from the main branch

This commit eases switching between the `main` and `5.3.x` branches.

spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework