rhpam-kogito-builder-rhel8 image is using a wrong label

The rhpam-kogito-builder-rhel8-overrides.yaml image descriptor was using the same component label than the runtime image, which needs to be updated to match the image purpose.

Needs to be changed from:

"rhpam-7-kogito-runtime-jvm-rhel8-container"

To:

"rhpam-7-kogito-builder-rhel8-container"