feat(api): soft-deprecate spec.targetNamespace field

[IrvingMg]

Changes

Soft-deprecate spec.targetNamespace on ShipwrightBuild. Operands now deploy in the operator's own namespace by default; the field is still honored with a deprecation warning.

Fixes #241

/kind feature

Submitter Checklist

• Includes tests if functionality changed/was added
• Includes docs if changes are user-facing
• Set a kind label on this PR
• Release notes block has been filled in, or marked NONE

See the contributor guide
for details on coding conventions, github and prow interactions, and the code review process.

Release Notes

action required: `spec.targetNamespace` is deprecated. Operands now deploy in the operator’s namespace by default. If you rely on a custom `targetNamespace`, the field is still honored but will be removed in a future release.

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign ayushsatyam146 for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[IrvingMg]

@shipwright-io/contributors PTAL