feat!: allow for configurability to zarf ignore the sandbox

[Racer159]

Description

This allows the user to configure whether the sandbox namespace is zarf ignored (with it ignored by default).

[!IMPORTANT]

:warning: BREAKING CHANGE:

• This PR will cause the zarf agent to ignore the sandbox namespace by default - jobs using the default images can still function but other images will not. In order to revert to the old behavior you need to override the sandboxZarfIgnore value in the uds-gitlab-runner-config chart and set the runners.job.registry and runners.helper.registry values according to the upstream values in your chosen flavor.

Related Issue

Fixes #87

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Other (security config, docs update, etc)

Checklist before merging

• [X] Test, docs, adr added or updated as needed
• [X] Contributor Guide Steps followed