Unable to configure targetAllocatorImage registry without specifying a tag

[alita1991]

I'm setting up Observability in an environment without internet access, where all required container images are hosted in a private registry.

Currently, I’m unable to configure the targetAllocatorImage by specifying only the registry. The configuration requires a tag to be explicitly set, which forces manual intervention after each update to adjust the tag accordingly.

This behavior creates friction when maintaining deployments in offline or restricted environments, as the version/tag needs to be managed manually instead of being automatically derived from the default image tag.

Proposed Solution

Enable support for specifying only the registry in the targetAllocatorImage configuration and default to the predefined image tag when none is explicitly set.